Plasma antioxidants are similarly depleted in mild cognitive impairment and in Alzheimer's disease

In order to assess peripheral levels and activities of a broad spectrum of non-enzymatic and enzymatic antioxidants in elderly subjects with mild cognitive impairment (MCI) and Alzheimer's disease (AD), plasma levels of water-soluble (Vitamin C and uric acid) and of lipophilic (Vitamin A, Vitamin E and carotenoids including lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha- and beta-carotene) antioxidant micronutrients as well as activities of plasma and red blood cell (RBC) superoxide dismutase (SOD) and of plasma glutathione peroxidase (GPx) were measured in 25 patients with MCI, 63 AD patients and 53 controls. Peripheral levels and activities of antioxidants were similarly lower in MCI and AD patients as compared to controls. As MCI may represent a prodromal stage of AD, and oxidative damage appears to occur as one of the earliest pathophysiological events in AD, an increased intake of antioxidants in patients with MCI could be helpful in lowering the risk of conversion to dementia.     

Gastric cytoprotective effects of vitamin A and other carotenoids

The effects of vitamin A and some carotenoids (beta-carotene, beta-cryptoxanthin, zeaxanthin, lutein, capsorubin, capsanthin, capsanthol and lycopene) were studied (a) on the development of acute gastric mucosal lesions produced by topical application of 0.6 M HCl and (b) on gastric secretion in 4-h pylorus-ligated rats. It was found (a) that vitamin A, beta-carotene, beta-cryptoxanthin, zeaxanthin and lutein significantly inhibited the development of gastric mucosal lesions produced by 0.6 M HCl, while capsorubin, capsanthin, capsanthol and lycopene failed to prevent the development of such lesions; and (b) that vitamin A, beta-carotene, beta-cryptoxanthin, zeaxanthin and lutein, i.e., the carotenoids which exerted a cytoprotective effect, had no inhibitory effect on gastric acid secretion in 4-h pylorus-ligated rats. The possible relationship between chemical structure and gastric cytoprotection is discussed.     

Associations between dietary antioxidant intake and oxidative stress in HIV-seropositive and HIV-seronegative men and women

OBJECTIVE: To describe the relationship between dietary antioxidant intake and oxidative stress in clinically stable HIV-positive and HIV-negative adults. DESIGN: A cross-sectional study. METHODS: Average total daily dietary intakes of vitamin C, beta-carotene, alpha-tocopherol, selenium, and zinc from foods and nutritional supplements were estimated in noninstitutionalized individuals using the dietary history method. Plasma malondialdehyde (MDA) concentrations were measured by high-performance-liquid-chromatography (HPLC) whereas peripheral blood mononuclear cell glutathione (PBMC GSH) concentrations were determined spectrophotometrically by an enzymatic recycling assay. Data were analyzed in multiple linear regression models to investigate these relationships. RESULTS: Regression analysis revealed an inverse relationship between selenium intake and plasma MDA in a model that included the five dietary antioxidants ( R 2 = 0.25; p < .02) and with selenium only ( R 2 = 0.19; p < .01). Both models were adjusted for gender, smoking status, and HIV seropositivity. Antioxidant intake was not associated with PBMC GSH ( R 2 = 0.12, p = .36). In univariate analyses, oxidative stress did not significantly differ between clinically stable HIV-positive and healthy HIV-negative study subjects. CONCLUSIONS: This is the first study to characterize the relationship between dietary antioxidant intake from food and supplements with oxidative stress. The results suggested dietary selenium intake was strongly and inversely associated with plasma MDA, but dietary antioxidant intakes were not related to PBMC GSH. This study also provides evidence that HIV infection was not specifically associated with oxidative stress among clinically stable individuals.     

Resonance Raman detection of carotenoid antioxidants in living human tissue

Increasing evidence points to the beneficial effects of carotenoid antioxidants in the human body. Several studies, for example, support the protective role of lutein and zeaxanthin in the prevention of age-related eye diseases. If present in high concentrations in the macular region of the retina, lutein and zeaxanthin provide pigmentation in this most light sensitive retinal spot, and as a result of light filtering and/or antioxidant action, delay the onset of macular degeneration with increasing age. Other carotenoids, such as lycopene and beta-carotene, play an important role as well in the protection of skin from UV and short-wavelength visible radiation. Lutein and lycopene may also have protective function for cardiovascular health, and lycopene may play a role in the prevention of prostate cancer. Motivated by the growing importance of carotenoids in health and disease, and recognizing the lack of any accepted noninvasive technology for the detection of carotenoids in living human tissue, we explore resonance Raman spectroscopy as a novel approach for noninvasive, laser optical carotenoid detection. We review the main results achieved recently with the Raman detection approach. Initially we applied the method to the detection of macular carotenoid pigments, and more recently to the detection of carotenoids in human skin and mucosal tissues. Using skin carotenoid Raman instruments, we measure the carotenoid response from the stratum corneum layer of the palm of the hand for a population of 1375 subjects and develop a portable skin Raman scanner for field studies. These experiments reveal that carotenoids are a good indicator of antioxidant status. They show that people with high oxidative stress, like smokers, and subjects with high sunlight exposure, in general, have reduced skin carotenoid levels, independent of their dietary carotenoid consumption. We find the Raman technique to be precise, specific, sensitive, and well suitable for clinical as well as field studies. The noninvasive laser technique may become a useful method for the correlation between tissue carotenoid levels and risk for malignancies or other degenerative diseases associated with oxidative stress.     

Stability of individual carotenoids, retinol and tocopherols in human plasma during exposure to light and after extraction.

We have modified gradient HPLC procedures for simultaneous quantification of retinol, gamma-tocopherol, alpha-tocopherol, lutein/zeaxanthin, beta-cryptoxanthin, trans-lycopene, cis-lycopene, alpha-carotene and beta-carotene in 200-microl aliquots of human plasma. The photosensitivity of these analytes in plasma exposed to fluorescent lighting for up to 72 h was investigated and most were stable under these conditions. The stability of these analytes held in darkness at -20 degrees C, 4 degrees C or room temperature for up to 48 h after extraction from plasma was also investigated. Variability in measurement of most analytes was greater at room temperature than at 4 degrees C or -20 degrees C. There were statistically significant variations in the measured concentrations of some analytes in samples kept cold. However, the magnitude of these variations was small and of little biological significance, particularly over the first 24 h.     

Concentrations of carotenoids,retinol and alpha-tocopherol in plasma and follicular fluid of women undergoing IVF

BACKGROUND: Carotenoids are transferred into follicular fluid where they might serve as antioxidants and/or as precursors of retinoids which might modulate follicular or oocyte functions. METHODS AND RESULTS: In 77 women undergoing IVF differences between plasma and follicular fluid in the levels of carotenoids, retinol and alpha-tocopherol were evaluated especially with regard to fertilization success. Concentration of total carotenoids, retinol and alpha-tocopherol determined by HPLC in follicular fluid and plasma were 0.06 +/- 0.02 versus 0.56 +/- 0.23 micro mol/l, 1.26 +/- 0.52 versus 1.66 +/- 0.37 micro mol/l and 4.89 +/- 2.13 versus 21.0 +/- 5.7 micro mol/l (mean +/- SD) respectively (P < 0.001 for all). Differences between plasma and follicular fluid were greater for beta-carotene and lycopene (<20% of plasma concentration) than for lutein and zeaxanthin (>40%). Intrafollicular retinol and retinol-binding protein (RBP) levels represented 58 +/- 23% and 60 +/- 19% of plasma level. Similar molar ratios of retinol/RBP were observed. While no differences in the mean values of all components investigated were observed in plasma and follicular fluid between women with and without reproductive success, the variability in the concentration was much greater in follicular fluid obtained from women without reproductive success. CONCLUSIONS: It remains to be elucidated, if this is indicative of a disturbed sieving effect of the blood-follicle barrier with possibly negative consequences for oocyte maturation.     

Oxidative stress in HIV-1-infected injection drug users

Low serum antioxidant levels observed in many HIV-infected populations could be largely due to an increase in oxidative stress (defined as a disturbance in the equilibrium status of prooxidant/antioxidant systems of intact cells). In HIV infection, oxidative stress may be caused by both overproduction of reactive oxygen intermediates (ROIs) and a simultaneous deficiency of antioxidant defenses. Furthermore, injection drug use has been associated with increased levels of oxidative stress in animal models. Currently, there is widespread use of self-prescribed antioxidant supplementation among the HIV-infected population and a prevailing belief that high-dose supplementation is beneficial, or at the very least, not harmful. Data from our studies show that HIV-positive injection drug users (IDUs) who are on antiretroviral combination therapies including a protease inhibitor have significantly higher mean serum levels of several antioxidants, independent of dietary and supplemental intake, compared with both HIV-negative IDUs and HIV-positive IDUs not taking protease inhibitors. This suggests that oxidative stress may be reduced in patients taking protease inhibitors. Preliminary data suggest that the future of antioxidant supplementation therapy, if any, will be one in which different doses of supplements are recommended for HIV-infected patients on the various antiretroviral treatment regimens. More research is needed to determine the interactions among injection drug use, oxidative stress, antiretroviral therapy, and the use of antioxidant supplements in HIV infection. Until more is known, caution should be exercised when using or recommending high-dose antioxidant supplementation in HIV-infected individuals, particularly in those on protease inhibitors, since moderate levels of oxidative stress are involved in a number of useful physiologic processes.     

Correlates of lending needles/syringes among HIV-seropositive injection drug users

Among HIV-positive injection drug users (IDUs), we examined the correlates of lending needles/syringes with HIV-negative and unknown status injection partners. HIV-positive IDUs (N=738) from 4 cities in the United States who reported injection drug use with other IDUs in the past 3 months participated in an audio computer-assisted self-administered interview. Eighteen percent of study participants self-reported having lent their needles to HIV-negative or unknown status injection partners. Multivariate analyses showed that 6 variables were significantly associated with this high-risk injecting practice. Older IDUs, high school graduates, and those reporting more supportive peer norms for safer drug use were less likely to lend needles/syringes. Admission to a hospital for drug treatment in the past 6 months, having injected with >1 person in the past 3 months, and having more psychiatric symptoms were all associated with more risk. These findings underscore the need for a continued prevention focus on HIV-positive IDUs that recognizes the combination of drug use, mental health factors, and social factors that might affect this high-risk injecting practice, which could be associated with HIV and hepatitis C transmission.     

Fat distribution in HIV-infected women in the United States: DEXA substudy in the Women's Interagency HIV Study

Surveys in HIV-infected men on antiretroviral therapy (ART) consistently demonstrate decreased levels of peripheral fat, with variable effects on central fat. This substudy of the Women's Interagency HIV Study was undertaken to examine fat distribution in a well-characterized cohort of HIV-positive and HIV-negative women in the United States. Whole-body dual-energy x-ray absorptiometry scanning with standardized regional analysis was performed in 271 nonpregnant women. Results were compared in the following groups: HIV negative (n = 88); and HIV positive on no ART (n = 70), highly active ART with a protease inhibitor (HAART/PI) (n = 48), or non-PI-containing HAART (n = 53). The groups were well matched with respect to race, with the majority of women coming from racial/ethnic minorities. The majority of both HIV-positive and HIV-negative women were overweight (body mass index [BMI] >/=25 kg/m), and many were obese (BMI >30 kg/m). Leg fat in both groups on HAART was significantly lower than in HIV-negative women (P = 0.01 and <0.0001 vs. HIV-negative for HAART/PI and HAART/no PI, respectively), whereas trunk fat was lower only in HAART/no PI (P = 0.0004 vs. HIV-negative). Thus, consistent with reports in men, lower levels of peripheral (leg) fat are seen in HIV-infected women on HAART, despite the high prevalence of obesity in this population.     

Physical fitness and plasma non-enzymatic antioxidant status at rest and after a wingate test.

We tested seven physical education students whether 30-s sprint anaerobic exercise (Wingate test) would result in oxidative stress (evaluated by lipid radical levels) sufficient to alter plasma non-enzymatic antioxidant status (plasma uric acid, ascorbic acid, alpha-tocopherol, beta-carotene). This study demonstrates that 1) Wingate test increases plasma uric and ascorbic acid concentrations (p <.05), and decreases plasma alpha-tocopherol and beta-carotene levels (p <.05); 2) lipid radical levels at rest and sprint performance are negatively correlated with resting plasma uric acid and alpha-tocopherol concentrations (p <.05). In conclusion, this study 1) demonstrates that a 30-s sprint anaerobic exercise is associated with acute changes in plasma non-enzymatic antioxidant status, 2) indicates that the subjects with largest leg peak power are those who exhibit the lowest plasma antioxidant status at rest (uric acid and alpha-tocopherol), 3) and suggests that antioxidant intake by maintaining plasma antioxidant concentration at rest in the normal range might protect athletes against oxidative stress induced by exercise.     

Effects of exogenous antioxidants on the levels of endogenous antioxidants, lipid-soluble fluorescent material and life span in the housefly, Musca domestica

Effects of exogenous antioxidant administration (0.5% and 2% ascorbate, beta-carotene and alpha-tocopherol in sucrose) on life-span, metabolic rate, activities of superoxide dismutase and catalase, levels of glutathione, inorganic peroxides and chloroform-soluble fluorescent material (lipofuscin) were examined in adult male houseflies. Administration of antioxidants at a level of 0.5% did not affect life-span, whereas, 2% ascorbate and alpha-tocopherol decreased average life-span. Metabolic rate of flies was unaffected, except by 2% ascorbate, which caused a decrease. Superoxide dismutase activity was depressed by 2% ascorbate at all ages, and by beta-carotene and alpha-tocopherol in older flies. Catalase activity was unaffected except by alpha-tocopherol at younger ages. Glutathione concentration was decreased by ascorbate and beta-carotene at both concentrations administered. Inorganic peroxides (H2O2) were increased by 2% beta-carotene and alpha-tocopherol. Only high concentrations of ascorbate and beta-carotene decreased the level of soluble fluorescent material. Results suggest that administration of exogenous antioxidants causes a compensatory depression of endogenous defenses.     

Lycopene synergistically inhibits LDL oxidation in combination with vitamin E, glabridin, rosmarinic acid, carnosic acid, or garlic

Several lines of evidence suggest that oxidatively modified low-density lipoprotein (LDL) is atherogenic, and that atherosclerosis can be attenuated by natural antioxidants, which inhibit LDL oxidation. This study was conducted to determine the effect of tomato lycopene alone, or in combination with other natural antioxidants, on LDL oxidation. LDL (100 microg of protein/ml) was incubated with increasing concentrations of lycopene or of tomato oleoresin (lipid extract of tomatoes containing 6% lycopene, 0.1% beta-carotene, 1% vitamin E, and polyphenols), after which it was oxidized by the addition of 5 micromol/liter of CuSO4. Tomato oleoresin exhibited superior capacity to inhibit LDL oxidation in comparison to pure lycopene, by up to five-fold [97% vs. 22% inhibition of thiobarbituric acid reactive substances (TBARS) formation, and 93% vs. 27% inhibition of lipid peroxides formation, respectively]. Because tomato oleoresin also contains, in addition to lycopene, vitamin E, flavonoids, and phenolics, a possible cooperative interaction between lycopene and such natural antioxidants was studied. A combination of lycopene (5 micromol/liter) with vitamin E (alpha-tocopherol) in the concentration range of 1-10 micromol/liter resulted in an inhibition of copper ion-induced LDL oxidation that was significantly greater than the expected additive individual inhibitions. The synergistic antioxidative effect of lycopene with vitamin E was not shared by gamma-to-cotrienol. The polyphenols glabridin (derived from licorice), rosmarinic acid or carnosic acid (derived from rosemary), as well as garlic (which contains a mixture of natural antioxidants) inhibited LDL oxidation in a dose-dependent manner. When lycopene (5 micromol/liter) was added to LDL in combination with glabridin, rosmarinic acid, carnosic acid, or garlic, synergistic antioxidative effects were obtained against LDL oxidation induced either by copper ions or by the radical generator AAPH. Similar interactive effects seen with lycopene were also observed with beta-carotene, but, however, to a lesser extent of synergism. Because natural antioxidants exist in nature in combination, the in vivo relevance of lycopene in combination with other natural antioxidants was studied. Four healthy subjects were administered a fatty meal containing 30 mg of lycopene in the form of tomato oleoresin. The lycopene concentration in postprandial plasma was elevated by 70% in comparison to plasma obtained before meal consumption. Postprandial LDL isolated 5 hr after meal consumption exhibited a significant (p < 0.01) reduced susceptibility to oxidation by 21%. We conclude that lycopene acts synergistically, as an effective antioxidant against LDL oxidation, with several natural antioxidants such as vitamin E, the flavonoid glabridin, the phenolics rosmarinic acid and carnosic acid, and garlic. These observations suggest a superior antiatherogenic characteristic to a combination of different natural antioxidants over that of an individual one.     

Status of selenium, vitamin E, and vitamin A among Saudi adults: potential links with common endemic diseases

This study was designed to determine the status of selenium, dl-alpha-tocopherol, and all-trans-retinol in adults living in Al-Kharj district using serum and toenail samples, and to look for possible association between these parameters and the etiology of endemic diseases in the same area. For this purpose, we examined a cross section of samples of 743 healthy Saudi adults on routine visits to the Primary Health Care Unites (PHCUs) for different common health problems. The arithmetic mean for selenium, dl-alpha-tocopherol, and all-trans-retinol in serum and toenail selenium levels were 107.045 +/- 23.045 microg/l (n = 743, range 52.600-210.120 microg/l), 1.053 +/- 0.324 mg/dl (n = 737, range 0.29-3.42 mg/dl), 52.561 +/- 25.671 microg/dl (n = 743, range 11.20-400.85 microg/dl), and 0.634 +/- 0.221 microg/g (n = 691, range < DL - 1.797 microg/g), respectively. The average serum selenium concentration seems to be satisfactory and compares favourably with high selenium intake countries. Although none of our participants exhibited serum selenium deficiency (< 45 microg/l), 41% of our participants had toenail selenium < 0.56 microg/g reported low levels in the previous study. The mean serum dl-alpha-tocopherol concentrations fall within the upper limit of the normal range of > 0.698-1.981 mg/dl for alpha-tocopherol as found in previous studies. On the other hand, the mean serum all-trans-retinol is higher than the normal range (20-30 microg/dl). None had exhausted retinol stores trans-retinol and MDA levels in the serum was found as a sign of peroxidative lipid damage, confirming the role of vitamin A in reducing oxidative stress. Our data also revealed a link between the status of selenium, dl-alpha-tocopherol and all-trans-retinol and a number of health problems. However, these observations need larger epidemiological studies for further confirmation.     

Are lutein and zeaxanthin conditionally essential nutrients for eye health?

The carotenoids lutein and zeaxanthin are found in the macula in high concentrations and may play a role in the pathogenesis of age-related macular degeneration (ARMD). Lutein and zeaxanthin may protect the macula and photoreceptor outer segments throughout the retina from oxidative stress and play a role in an antioxidant cascade that safely disarms the energy of reactive oxygen species. Although lutein and zeaxanthin are not essential nutrients, studies are beginning to suggest that they fit the criteria for conditionally essential nutrients. Low plasma lutein and zeaxanthin concentrations or dietary intake are associated with low macular pigment density and increased risk of ARMD. Dietary deprivation of lutein and zeaxanthin in primates causes pathological changes in the macula. Should controlled clinical trials show lutein and/or zeaxanthin supplementation protects against the development or progression of ARMD and other eye diseases, then lutein and zeaxanthin could be considered as conditionally essential nutrients for humans.     

Immune activation and oxidative damage in HIV-positive and HIV-negative adolescents

In a cross-sectional study involving subjects from the Reaching for Excellence in Adolescent Health cohort, we examined the associations between HIV status, disease severity, immune activation, and oxidative damage. Subjects (265 HIV-positive and 127 HIV-negative) were young (range: 14-23 years of age) and primarily female (75%) and black (67%). Many subjects, particularly female subjects, were overweight or obese. Relatively few HIV-positive subjects had advanced HIV disease (13%), and 54% were taking antiretroviral therapy (ART). The 2 markers of oxidative damage used in this study (plasma malondialdehyde and protein carbonyl concentrations) did not correlate with each other, and neither was higher in HIV-positive subjects than in HIV-negative controls. Increased oxidative damage was seen in association with male gender, cigarette smoking, marijuana use, immune activation (as indicated by activated CD8 T-cell counts and plasma C-reactive protein concentration), and use of ART, however. Plasma ceruloplasmin was associated with decreased oxidative damage in HIV-positive subjects, although this association was not seen in those taking ART.     

Role of beta2-glycoprotein I, LDL-, and antioxidant levels in hypercholesterolemic elderly subjects

The levels of electronegative low-density lipoprotein (LDL-), LDL cholesterol oxidability, and plasma levels of molecular antioxidants and of beta(2)-glycoprotein I (beta(2) GPI) were studied in a group of 10 hypercholesterolemic (HC) and 10 normocholesterolemic (NC) elderly subjects. HC subjects showed significantly higher levels of cholesterol, LDL cholesterol, LDL-, and beta(2)GPI than NC, whereas high-density lipoprotein cholesterol and alpha-tocopherol levels were lower in HC as compared with NC subjects. Correlations among LDL- levels, LDL oxidation lag time, beta(2)GPI, and antioxidant plasma levels were studied in 100 HC elderly subjects. Lag time for in vitro LDL oxidation positively correlated with ubiquinol-10 levels (p = 0.008), but not with other antioxidants studied or beta(2)GPI. LDL- and alpha-tocopherol levels showed an inverse and significant correlation (p = 0.018). beta(2)GPI and LDL cholesterol levels were correlated (p = 0.001), whereas no significance was found between LDL- and beta(2)GPI levels (p = 0.057). The physiological significance of alpha-tocopherol and ubiquinol-10 levels on LDL- levels, and the presence of high levels of beta(2)-GPI, are discussed in terms of protective mechanisms operating during the overall atherosclerosis process.     

Dietary micronutrients/antioxidants and their relationship with bronchial asthma severity

BACKGROUND: Because little is known about micronutrient/antioxidant intake and asthma severity, we investigated dietary intake and plasma/serum levels of micronutrients/antioxidants in a group of asthma patients with various degrees of severity, and compared the results with healthy subjects. METHODS: A case control study was carried out on 118 asthma patients and 121 healthy subjects. The severity of the disease was classified by division of patients into four groups. Normal dietary micronutrient/antioxidant intake was estimated from a food frequency questionnaire. Plasma/serum levels of vitamins C, E, and A, selenium, magnesium, zinc, and platelet glutathione peroxidase (GSH-Px) activity were also determined. RESULTS: No differences in daily micronutrient/antioxidant intake were seen between patients and healthy subjects. The severity of the disease showed no significant relationship with micronutrient/antioxidant intake. There were no differences in plasma/serum levels in any of the micronutrients/antioxidants between healthy subjects and asthmatics. Nor were any differences found between asthma groups in severity in the biochemical measures, except in platelet GSH-Px activity, which was significantly lower in the most severe groups. CONCLUSIONS: In this study, we found no evidence of any association between micronutrient/antioxidant intake or plasma/serum levels of micronutrients/antioxidants and asthma. Reduction of platelet GSH-Px activity in the most severe patients suggests that these patients have a diminished capacity to restore part of the antioxidant defences.     

Females experiencing sexual and drug vulnerabilities are at elevated risk for HIV infection among youth who use injection drugs

OBJECTIVES: To compare sociodemographic, drug-related, and sexual risk variables between young (13-24 years of age) and older (> or =25 years of age) injection drug users (IDUs); and to determine HIV prevalence and associated risk factors for HIV infection among young IDUs. METHODS: Data were collected through the Vancouver Injection Drug Users Study (VIDUS). To date, over 1400 Vancouver area IDUs have been enrolled and observed during follow-up. Sociodemographic, drug-related, and sexual risk variables were compared between younger and older IDUs using nonparametric methods. Mantel-Haenszel and logistic regression methods were used to compare HIV-positive and HIV-negative female youth. RESULTS: Younger injectors (N = 232) were more likely to be female; work in the sex trade; report condom use; inject heroin daily; smoke crack cocaine daily; and need help injecting. HIV prevalence at baseline among the youth was 10%. HIV prevalence was associated with female gender; history of sexual abuse; engaging in survival sex; injecting heroin daily; injecting speedballs (a mixture of heroin and cocaine) daily; and having numerous lifetime sexual partners. CONCLUSION: Our data show that HIV positivity among young IDUs is concentrated among females engaged in dual sexual and drug-related risk exposure categories. Over half the HIV-positive youth were Aboriginal (a classification used by the federal government in Canada to include native peoples of all ethnic groups). Targeted interventions that take into account sexual and drug risk for young female and Aboriginal peoples are urgently needed.     

Immunoglobulin levels amongst persons with and without human immunodeficiency virus type 1 infection in Uganda and Norway

CD4+-cell count and viral load monitoring are expensive and unavailable to most human immunodeficiency virus (HIV)-infected people in Africa. In an attempt to evaluate alternative methods for monitoring antiretroviral (ARV) therapy, we measured concentrations of immunoglobulin (Ig)A, IgM, IgG and IgG1 amongst adults with and without HIV in Uganda and Norway. We adjusted for disease severity by stratifying HIV-positive subjects on CD4+-cell counts above and below 200 cells/ micro l. Median serum levels of IgG, IgG1 and IgA were significantly higher in HIV-positive persons compared with HIV-negative persons in both countries (P < 0.001 and P = 0.018 for IgA in Ugandan patients). Levels of IgA in Ugandan HIV-negative subjects were significantly lower than those in HIV-positive subjects with low CD4+ compared with those with high CD4+-cell counts (P < 0.001 and P = 0.069, respectively). IgM levels were different between the HIV-negative and the two HIV-positive groups in Norway (P < 0.001). The mean levels of IgM, IgG and IgG1 in HIV-negative and -positive African subjects were generally higher than those in comparable groups of Western subjects. Our results verify that levels of IgA, IgG and IgG1 vary between HIV-negative and -positive individuals in both study populations. Their determination may be useful in monitoring both disease progression and response to ARV therapy.