Evaluation of the use of dried spots and of different storage conditions of plasma for HIV-1 RNA quantification

OBJECTIVES: The aim of the study was to evaluate the use of dried plasma spots to determine HIV-1 RNA viral loads. METHODS: The viral loads of 30 liquid plasma samples were compared with those of corresponding dried plasma spots on filter paper (DPS-FP) and in tubes (DPS-T), both of which were left for 7 days at 22 degrees C. Also, 10 liquid plasma samples with detectable viral load were stored at 4, 22 or 37 degrees C for 7 days and five further liquid plasma samples were air-dried for up to 54 h to assess the effects of temperature and the drying step on HIV-1 viral load. RESULTS: The viral loads of the 30 liquid plasma samples correlated significantly with those of the paired dried spots DPS-FP and DPS-T, but with median losses of 0.64 and 0.69 log(10) HIV-1 RNA copies/mL, respectively, and a limit of detection of 3 log(10) copies/mL. The 10 liquid plasma samples stored for 1 week at 37 degrees C showed a weaker correlation and had a significantly reduced median viral load (-0.92 log(10); P=0.005) when compared with the viral load of the matched plasma stored at - 80 degrees C. Most of the loss happened during the drying step. CONCLUSIONS: Reliable measurement of HIV-1 RNA viral load requires good plasma storage conditions. HIV RNA stability was affected by desiccation and 1 week of storage at 37 degrees C. However, our findings suggest that liquid plasma can be kept at 4 or 22 degrees C for a week with no effect on viral load.     

Use of dried whole blood spots to measure CD4+ lymphocyte counts in HIV-1-infected patients

As antiretroviral drugs become widely available in developing countries, practical, field-friendly, and cheap methods of measuring CD4+ lymphocyte counts need to be developed. We tested use of whole blood spots dried on filter paper to measure CD4+ lymphocyte counts. We obtained blood from 42 HIV-1-infected patients from Zambia. We dried blood spots on filter paper and measured CD4+ lymphocyte counts with an established commercial enzyme immunoassay. We compared these measurements with those obtained from matched liquid whole-blood samples analysed with standard flow cytometry. Results of the filter-paper method accorded well with flow cytometry CD4 counts greater than 200 cells/microL (mean difference 13.6 [SD 52.4]). Dried whole blood stored on filter paper could be developed into a field-friendly alternative for CD4+ lymphocyte count measurements.     

Implementation of HIV early infant diagnosis and HIV type 1 RNA viral load determination on dried blood spots in Cameroon: challenges and propositions

The testing of dried blood spots (DBSs) for human immunodeficiency type 1 (HIV-1) proviral DNA by PCR is a technology that has proven to be particularly valuable in diagnosing exposed infants. We implemented this technology for HIV-1 early infant diagnosis (EID) and HIV-1 RNA viral load determination in infants born of HIV-1-seropositive mothers from remote areas in Cameroon. The samples were collected between December 2007 and September 2010. Fourteen thousand seven hundred and sixty-three (14,763) DBS samples from infants born of HIV-positive mothers in 108 sites nationwide were tested for HIV. Of these, 1452 were positive on first PCR analyses (PCR1), giving an overall infection rate of 12.30%. We received only 475 DBS specimen for a second PCR testing (PCR2); out of these, 145 were positive. The median HIV-1 RNA viral load for 169 infant DBS samples tested was 6.85 log copies/ml, with values ranging from 3.37 to 8 log copies/ml. The determination of the viral load on the same DBS as that used for PCR1 allowed us to bypass the PCR2. The viral load values were high and tend to decrease with age but with a weak slope. The high values of viral load among these infants call for early and effective administration of antiretroviral therapy (ART). The findings from this study indicate that the use of DBS provides a powerful tool for perinatal screening programs, improvement on the testing algorithm, and follow-up during treatment, and thus should be scaled up to the entire nation.     

Lower levels of HIV RNA in semen in HIV-2 compared with HIV-1 infection: implications for differences in transmission

BACKGROUND AND OBJECTIVES: HIV-2 infection, in comparison with HIV-1, is characterized by lower plasma viral loads, slower CD4 cell count decline, decreased AIDS-related mortality, and lower rates of mother-to-child and sexual transmission. To gain further insight into why HIV-1 is more readily transmitted as compared with HIV-2, we analyzed semen and plasma HIV RNA levels in HIV-1 and HIV-2-positive men from Senegal. DESIGN AND METHODS: Twenty-two HIV-1 and 10 HIV-2-infected subjects from the University of Dakar donated semen and blood samples for this analysis. HIV-1 and HIV-2 viral loads in semen and plasma were quantified using type-specific polymerase chain reaction assays. RESULTS: The mean age of the subjects was 37 and 40 years; mean CD4 cell count was 222 and 276 cells/microl and the mean plasma viral load was 4.7 and 3.0 log10 copies/ml for HIV-1 and HIV-2, respectively (P = 0.002). HIV RNA was detected in semen in 21 of 22 (95%) of HIV-1 and seven of 10 (70%) of HIV-2-infected subjects; P = 0.07). However, the levels of HIV RNA present in semen were markedly different between those with HIV-1 and HIV-2, with a mean of 4.4 log10 copies/ml among those with HIV-1 and a mean of 2.6 log10 copies/ml among those with HIV-2 (P < 0.001). In multivariate analysis, plasma viral load and HIV type, but not CD4 cell count, were independently predictive of semen viral load (P = 0.03, 0.05, 0.48, respectively) CONCLUSIONS: These data suggest that differences in semen viral load between HIV-1 and HIV-2 may be in part responsible for the markedly different transmission rates of these two viruses. In addition, risk of male genital tract shedding strongly correlates with plasma viral loads. Interventions that decrease viral load may help decrease transmission of both HIV-1 and HIV-2.     

Utilidad de los dried blood spots para monitorizar la infección por virus de la inmunodeficiencia humana en los programas de salud pública de países en desarrollo

As access to antiretroviral treatment increases in the developing countries, efforts towards making it easier and less costly to collect, store, and deliver the biological samples to reference laboratories, where the serological and genetic diagnosis techniques are performed, have become a high priority. Blood sampling on filter papers is an inexpensive and practical alternative to plasma for antiretroviral treatment monitoring in countries with limited resources and no access to cold chains or refrigeration. The main clinical applications and uses of blood-sampling onto filter papers (dried blood spots [DBS]) are reviewed, focusing on how these can be applied in monitoring HIV infection, particularly for use in National Health Programs in developing countries, or in resource-limited settings. A review is presented of studies that have used the DBS technique for quantifying viral load, analysis of antiretroviral drug-resistance mutations, early infant diagnosis, adult serological diagnosis, detection of viral p24 antigen, and molecular epidemiology of HIV-1, in different geographical locations. Those variables that could affect the use of DBS, particularly in the HIV field, as well as explaining how these procedures can be optimised to increase their sensitivity are also reviewed. The aim of this study was to review the advantages of implementing the DBS technique in the HIV field, especially in resource-constrained regions.     

Differences in HIV-2 plasma viral load and immune activation in HIV-1 and HIV-2 dually infected persons and those infected with HIV-2 only in Abidjan, Côte D'Ivoire

OBJECTIVE: To determine whether blood plasma levels of HIV-2 RNA viral loads and immune activation markers differ between persons infected with HIV-2 only and those dually infected with HIV-1 and HIV-2. METHODS: Between September 1996 and February 2000, we collected, analyzed and compared levels of HIV-2 RNA in plasma and immune activation markers among 52 persons infected with HIV-2 alone and 75 with confirmed dual infection. We also compared viral load and immune activation in patients who were infected with HIV-1 only and those who were dually infected. RESULTS: When we conducted a CD4 T-cell count-stratified multivariate analysis of HIV-2 viral load, controlling for difference in CD4 T-cell counts, age and sex: at < 200 x 10 CD4 T cells/l, HIV-2 viral load was 2.0 log10 copies/ml lower in dually infected patients than in HIV-2 only patients (P < 0.0001). At CD4 T-cell counts between 200 x 10 and 500 x 10/l, HIV-2 viral load was 0.3 log10 copies/ml lower in dually infected patients (P = 0.45). However, at CD4 T-cells counts > 500 x 10/l, HIV-2 viral load was 0.9 log10 copies/ml higher in dually infected patients (P < 0.0001). Dually infected persons with undetectable HIV-2 viral loads had significantly higher median levels of CD8 T cells expressing CD38 (P < 0.001) and HLA-DR (P = 0.01) than HIV-2 only infected patients. CONCLUSION: These results suggest that in dual infection, the level of HIV-2 replication depends on the immune status of the patients, with HIV-1 out-replicating HIV-2 as disease progress.     

Cerebrospinal fluid HIV-1 RNA levels in asymptomatic patients with early stage chronic HIV-1 infection: support for the hypothesis of local virus replication.

OBJECTIVE: To assess HIV-1 RNA levels in cerebrospinal fluid (CSF) and their potential correlation with plasma viral load and central nervous system (CNS) HIV-1 infection markers in stable asymptomatic patients with a CD4 T cell count >500x10(6) cells/l. PATIENTS AND METHODS: Consecutive patients screened for two trials were eligible for lumbar puncture assessment. At day 0, simultaneous samples of CSF and plasma were obtained and levels of total proteins, albumin, IgG, antibodies against HIV-1 p24 antigen, HIV-1 RNA (using the polymerase chain technique) and white cells were measured. RESULTS: The integrity of the blood-brain barrier was preserved (albumin index > or =7) in 59 out of 70 patients (84%). Intrathecal production of antibodies against HIV-1 p24 antigen was demonstrated in 55 out of 70 individuals (78%). Viral load in CSF was significantly lower than plasma values (3.13+/-0.95 versus 4.53+/-0.53, P = 0.0001). HIV-1 RNA was not detected in CSF in only three of the 70 patients (4%). Overall, there was a significant correlation between plasma and CSF HIV-1 RNA levels (r = 0.43, P = 0.0001); however, in 29 patients (41%) there were significant differences (>1.5 log10 copies/ml) between the viral loads in plasma and CSF. In the multivariate analysis, a high level of protein and white cells in CSF, but not the HIV-1 RNA plasma level, were factors independently associated with a higher level of HIV-1 RNA in CSF (P = 0.0001). CONCLUSIONS: HIV-1 RNA can be detected almost always in CSF of asymptomatic patients in early stages of HIV-1 infection including those with a preserved integrity of the blood-brain barrier. The important discrepancies between plasma and CSF viral load, and the independent association between CSF abnormalities and CSF viral load, support the hypothesis of local production of HIV-1.     

The virological and immunological consequences of structured treatment interruptions in chronic HIV-1 infection.

BACKGROUND: Some individuals with chronic HIV-1 infection have discontinued their drug therapy with consequent plasma virus rebound. In a small number of patients, a delayed or absent rebound in plasma virus load has been noted after drug cessation, apparently associated with prior drug interruptions and autologous boosting of HIV-1 specific immune responses. We hypothesized that cyclic structured treatment interruptions structured treatment interruptions (STI) could augment HIV-1 specific immune responses in chronic HIV-1 infection, which might help to control HIV-1 replication off therapy. METHODS: We initiated an STI pilot study in 10 antiretroviral treatment-naive HIV-1 chronically infected subjects with baseline CD4 T-cell counts > 500 x 10(6) cells/l and plasma viral load > 5000 copies/ml who received highly active antiretroviral therapy (HAART) for 1 year with good response (plasma viral load < 20 copies/ml for at least 32 weeks). Three cycles of HAART interruption were performed. RESULTS: In all of the patients viral load rebounded, but doubling times increased significantly between the first and third stops (P = 0.008), and by the third stop, six out of nine subjects had a virological set-point after a median 12 months off therapy that was lower than baseline before starting HAART (ranging from 0.6 log(10) to 1.3 log(10) lower than baseline) and in four it remained stable below 5000 copies/ml. Those subjects who controlled viral replication developed significantly stronger HIV-1 specific cellular immune responses than subjects lacking spontaneous decline (P < 0.05). During viral rebounds no genotypic or phenotypic changes conferring resistance to reverse trancriptase inhibitors or protease inhibitors was detected, but mean absolute CD4 T-cell counts declined significantly, although never below 450 x 10(6)/l and the mean value at 12 months off therapy was significantly higher than the pre-treatment level (P = 0.004). CONCLUSIONS: Our findings suggest that STI in chronic HIV-1 infection might augment HIV-1-specific cellular immune responses associated with a spontaneous and sustained drop in plasma viral load in some subjects but at the potential cost of lower CD4 T-cell counts.     

Plasma RNA viral load predicts the rate of CD4 T cell decline and death in HIV-2-infected patients in West Africa

OBJECTIVE: To examine whether the levels of plasma RNA and DNA provirus predict the rate of CD4 cell decline and patient death. DESIGN: Retrospective analysis of HIV-2 cohort subjects. METHODS: Fifty-two subjects were recruited between January 1991 and December 1992. HIV-2 RNA levels in plasma and DNA levels in peripheral blood mononuclear cells (PBMC) were measured using in-house quantitative PCR assays. The annual rate of CD4 cell decline was calculated using the least-squares method. The survival data on 31 December 1997 were used. RESULTS: The mean percentage of CD4 cells at baseline was 30.7 (SD, 9.5). In a linear regression model, the annual rate of CD4 cell decline was 1.76 CD4% faster for every increase in one log10 RNA copies/ml [95% confidence interval (CI), 0.81-2.7; P = 0.0006; r = 0.46; n = 52] and 1.76 CD4% faster for every increase in log10 DNA copies/10(5) PBMC (95% CI 0.46-3.1; P = 0.01; r = 0.33; n = 42). In a multiple linear regression model, RNA load was related to CD4 decline independently of DNA load (P = 0.02). The overall mortality rate was 7.29/100 person-years. In a Cox regression model, the hazard rate increased by 2.12 for each log10 increase in RNA load (95% CI, 1.3-3.5; P = 0.0023) but only by 1.09 for each log10 increase in DNA load (95% CI, 0.64-1.87; P = 0.8). CONCLUSION: This longitudinal study shows for the first time that a baseline HIV-2 RNA load predicts the rate of disease progression. HIV-2-infected patients with a high viral load may need to be treated as vigorously as HIV-1 patients.     

Quantification of RNA in HIV type 1 subtypes D and G by NucliSens and Amplicor assays in Abidjan, Ivory Coast

We have compared the performance of the NucliSens and the standard and modified HIV Monitor assays to quantify HIV-1 RNA plasma viral load in 12 tuberculosis patients infected with HIV-1 env subtype D (n = 3) and env subtype G (n = 9) in Ivory Coast. RNA was quantified in all nine subtype G specimens by the modified Amplicor HIV Monitor (mean, 4.6 log10 copies/ml; range, 3.1-6.3 log10/ml), in seven specimens by NucliSens (mean, 4.4 log10 copies/ml; range, 2.7-5.5 log10 copies/ml), and in 6 specimens by the standard Amplicor HIV Monitor assay (mean, 4.2 log10 copies/ml; range, 3.5-5.0 log10 copies/ml). All three subtype D samples were amplified by both the modified Amplicor HIV Monitor (mean, 4.5 log10 copies/ml; range, 3.8-5.1 log10 copies/ml) and NucliSens (mean, 3.8 log10 copies/ml; range, 2.8-5.0 log10 copies/ml); two samples were quantified by the standard Amplicor HIV Monitor assay (mean, 3.0 log10 copies/ml; range, 2.4-3.6 log10 copies/ml). Our preliminary results suggest that the modified Amplicor HIV Monitor can accurately quantify HIV-1 RNA viral load in persons infected with subtype D and G strains.     

Dual infection with human immunodeficiency virus type 1 and type 2: impact on HIV type 1 viral load and immune activation markers in HIV-seropositive female sex workers in Abidjan, Ivory Coast

To determine the impact of dual infection with HIV-1 and HIV-2 on HIV-1 viral load and markers of immune activation among HIV-seropositive FSWs in Abidjan, we analyzed blood samples obtained from consenting HIV-seropositive FSWs attending a confidential clinic between September 1996 and June 1997 in Abidjan. Among HIV-1 and HIV-2 dually seropositive FSWs, polymerase chain reaction (PCR) testing with HIV-1 and HIV-2 primers was used to differentiate between FSWs who were PCR positive only for HIV-1 and those positive for both HIV-1 and HIV-2 (dually infected). Of the 203 FSWs, 151 (74%) were HIV-1 seropositive only (median age, 26 years), 4 (2%) were HIV-2 seropositive, and 48 (24%) were dually seropositive (median age, 30 years). Of the 48 dually seropositive FSWs, 33 (69%) were dually infected and 15 (31%) were dually seropositive. Median CD4+ T cell counts per microliter were not significantly different among the three groups (525 for HIV-1 positive only, 502 for dually infected, and 416 for dually seropositive) (p = 0.14). Median viral load (log10 copies/ml) was not significantly different among the HIV-1-only FSWs (4.8 log10 copies/ml) compared with the 32 dually infected FSWs (4.6 log10 copies/ml) and 14 dually seropositive FSWs (4.7 log10 copies/ml; p = 0.95). Median levels of HLA-DR immune activation were increased in both CD4+ and CD8+ T cells for the dually infected (n = 27) FSWs compared with those infected with HIV-1 only (n = 123) (p = 0.019 and p = 0.01, respectively). Dual infection does not appear to influence levels of HIV-1 viral load in vivo. However, levels of HLA-DR are higher among FSWs dually infected with HIV-1 and HIV-2 than among those infected with HIV-1 only.     

Maternal plasma viral load, zidovudine and mother-to-child transmission of HIV-1 in Africa: DITRAME ANRS 049a trial

OBJECTIVE: To study the relationship between maternal plasma RNA levels and mother-to-child transmission (MTCT) of HIV-1 in African breastfed children. DESIGN: Nested case-control study within a randomized trial assessing the efficacy of a short maternal zidovudine (ZDV) regimen to reduce MTCT. METHODS: Eligible women received either 300 mg of ZDV twice a day until labour, 600 mg at the beginning of labour and 300 mg twice a day for 7 days post-partum or a placebo. The diagnosis of paediatric HIV-1 infection was based on PCR tests at days 1--8, 45, 90 and 180 then on serology performed at 3 monthl intervals. Plasma HIV-1 RNA was measured at inclusion and on day 8 after delivery for all women who did transmit HIV to their children (cases) using a Chiron branched DNA assay (sensitivity 50 copies/ml) and compared with women who did not transmit (two per case) matched for phase trial, treatment allocation and site. RESULTS: At inclusion, mean log10 viral load was 4.6 among 55 transmitting mothers and 3.7 among 117 non transmitters (P = 0.0001). Among transmitters, the mean difference in log10 viral load between day 8 post-partum and inclusion was -0.13 in the ZDV group (n = 23) versus 0.27 in the placebo group (n = 32; P = 0.01); among non transmitters it was -0.35 for the ZDV group (n = 47) versus 0.27 in the placebo group (n = 70; P < 10(-4)). In multivariate logistic regression analysis, odds ratios for MTCT were 8.7 (95% confidence interval, 3.7-20.6) for 1 log(10) increase of maternal RNA at inclusion and 4.2 (95% confidence interval, 1.7--10.3) for 1 log(10) increase difference from inclusion to day 8 post-partum. CONCLUSION: High maternal viral load at inclusion strongly predicts MTCT of HIV in Africa. A short ZDV treatment regimen decreases significantly maternal viral load from its pretreatment level.     

Association of genital shedding of herpes simplex virus type 2 and HIV-1 among sex workers in rural Zimbabwe

INTRODUCTION: Herpes simplex virus type 2 (HSV-2) facilitates sexual acquisition of HIV-1 but data on transmission are less clear. In this study the interaction between genital shedding of HIV-1 and HSV-2 was explored among Zimbabwean sex workers. METHODS: Women (n = 214) were interviewed about genital symptoms. Blood samples were analysed for HIV-1 and HSV-2 antibodies, HIV-1 plasma viral load (PVL) and CD4 lymphocyte count and genital swabs for detection of HIV-1 and HSV-2 genital shedding, Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis, and a cervico-vaginal lavage (CVL) for quantitative measurement of HIV-1 shedding. Shedding analyses were undertaken on women co-infected with HSV-2 and HIV-1. RESULTS: A total of 124 women were co-infected with HIV-1 and HSV-2; 58 were infected with HSV-2 alone. Most HIV-1-infected women were co-infected with HSV-2 (95.4%). Genital HIV-1 shedding was detected in 84.3% of co-infected women and was associated with low CD4 cell count and high PVL but not with reported symptoms of genital herpes or genital shedding of HSV-2. There was no difference in HIV-1 shedding among women shedding HSV-2 (79.3%) and women not shedding HSV-2 (83.2%) (P = 0.64). The adjusted odds ratio for HIV-1 shedding between HSV-2 shedders and non-shedders was 0.8 [95% confidence interval (CI), 0.2-3.3]. HIV-1 PVL(log10) and CVL viral load(log10) were correlated (r = 0.38; 95%CI, 0.2-0.5). After adjusting for PVL, genital symptoms and age, HSV-2 shedding had no effect on CVL viral load (P = 0.13). CONCLUSION: Rate and quantity of HIV-1 genital shedding do not appear to be altered by presence of HSV-2 genital shedding.     

Treatment of intestinal helminths does not reduce plasma concentrations of HIV-1 RNA in coinfected Zambian adults

BACKGROUND: Infection with intestinal helminths may stimulate dysfunctional immune responses in human immunodeficiency virus (HIV)-infected persons. Studies have yielded conflicting results regarding the impact of antihelminthic treatment on plasma concentrations of HIV-1 RNA.Methods. We conducted a prospective study of 54 HIV-1- and helminth-coinfected and 57 HIV-1-infected, helminth-uninfected asymptomatic adults living in Lusaka, Zambia, to assess the impact of antihelminthic treatment on plasma concentrations of HIV-1 RNA. RESULTS: Median baseline viral load was 0.33 log(10) copies/mL lower in the helminth-infected group than in the uninfected group. Mean viral load between pretreatment and posttreatment visits increased in the helminth-infected (mean, 4.23 vs. 4.29 log(10) copies/mL; P=.6) and helminth-uninfected (mean, 4.39 vs. 4.52 log(10) copies/mL; P=.2) groups. Helminth-infected participants with high pretreatment viral loads had a mean 0.25-log(10) copies/mL decrease after treatment (P=.3), and helminth-uninfected participants had a mean 0.02-log(10) copies/mL decrease (P=.8). CONCLUSIONS: We did not find an overall association between treatment of intestinal helminth infections and reduction in viral load in coinfected adults. Future studies may need to focus on adults with intense helminth infections who live in rural areas or on adults or children who harbor higher helminth burdens and plasma concentrations of HIV-1 RNA.     

Inverse relationship between viral load and genotypic resistance mutations in Korean patients with primary HIV type 1 infections

The transmission of antiretroviral-resistant HIV-1 strains is associated with suboptimal virological responses to initial antiretroviral therapy. However, certain types of resistance mutations are known to be associated with decreased viral fitness, which confers a lower replication capacity than that of the wild-type virus in the absence of antiretroviral drugs. Therefore, we evaluated the relationship between antiretroviral resistance mutations and viral replication in the primary HIV-1 infection (PHI) period. From January 2002 to March 2005, 52 PHI patients were identified in the Republic of Korea. HIV-1 RNA genotyping was performed, and the resistance mutation score was obtained from the HIV Drug Resistance Database of Stanford University. We defined the sum of the average resistance mutation scores (SARMS) for each antiretroviral drug class as a measure of the degree of resistance of any specific strain. The overall mean SARMS was 2.00 +/- 2.74, and the annual mean did not change significantly during the study period. No critical resistance mutation gene was identified in the study group. The SARMS showed a weak negative correlation with the viral load log10 during PHI, but without statistical significance (r = -0.274, p = 0.051). But the mean SARMS of patients with a viral load exceeding 100,000 copies/ml was significantly lower than that of patients with a viral load of less than 100,000 copies/ml (p = 0.03). Evaluation of the potency of antiretroviral resistance revealed a weak negative correlation with viral replication in the PHI period. This could be one reason why the transmission of resistant strains in PHI patients is not increasing significantly despite the widespread use of highly active antiretroviral therapy (HAART).     

HIV-1 RNA concentration and cognitive performance in a cohort of HIV-positive people

OBJECTIVE: To determine whether higher viral concentrations in the cerebrospinal fluid (CSF) and/or peripheral blood were associated with greater severity of cognitive impairment in HIV-1-seropositive subjects with cognitive-motor impairment. METHODS: Cognitive performance measurements and viral load were obtained from HIV-1-seropositive individuals with cognitive-motor impairment entering a clinical trial before the introduction of highly active antiretroviral therapy (HAART). CSF viral load (UltraSensitive Roche HIV-1 Monitor test with detection limit of 50 copies/ml) was available from 179 patients, and peripheral (plasma or serum) viral load from 111 patients. Of these patients, 62% met the 1993 Centers for Disease Control (CDC) criteria for AIDS, and 19% had clinically significant cognitive impairment (i.e., global deficit score > or = 0.5). Possible associations between viral load and cognitive scores were examined with general linear regression models with and without adjustment for age, education, study site, antiretroviral use, CD4 cell count, and CDC stage. RESULTS: The mean CSF viral load was 2.83 log(10)/ml +/- 0.94 (SD) (undetectable in 19.5%). Mean peripheral viral load was 4.11 log(10)/ml +/- 0.90 (SD). No statistically significant associations emerged between either CSF or peripheral viral load and the global deficit score, or any of the seven cognitive domain deficit scores. CONCLUSIONS: Among these HIV-1-sero-positive individuals with mainly minor HIV-1-associated cognitive deficits and not receiving HAART, no association between CSF or blood concentration of HIV-1 RNA and cognitive performance could be found. These results suggest that the severity of HIV-1-associated cognitive impairment is not directly related to concurrent viral concentration in the CSF or the peripheral blood.     

Consistent subtype-specific anti-HIV type 1 T lymphocyte responses in Indian subjects recently infected with HIV type 1

Anti-HIV-1-specific T cell responses in early HIV-1 infection have been found to be important in deciding the course of disease progression. But there are few data concerning nonsubtype B HIV infection. HIV-1 subtype C is the most prevalent subtype in India. HIV-1 Gag-specific T cell responses in 12 Indian subjects with recent HIV-1 infection were characterized by an ELISpot assay at two consecutive visits and their correlation with plasma viral load and CD4(+) T lymphocyte counts was studied. Ten of the 12 subjects demonstrated T cell responses to either one or both Gag B and C peptides, on at least one visit. Five of 10 responders showed a consistent response (response at both visits): 4 exhibited a Gag C-specific consistent response and 1 showed a consistent response to Gag B. The remaining five patients, showing response at only one of the two visits, were considered inconsistent responders. None of the individuals showed a consistent response to both B and C Gag peptides. Marginally significant correlation was observed between consistency of the response and lower plasma viral load (p = 0.062). The subtype-specific Gag C response was also found to be correlated with lower viral load as compared with the response to Gag B (r = -0.336, p = 0.054 for subtype C and r = -0.234, p = 0.13 for subtype B). The data suggest that the patients exhibiting consistent subtype-specific responses to HIV-1 Gag might have better control of viral replication in early HIV infection.     

两种HIV-1核酸定量检测试剂盒v2．0的对比研究

目的 比较罗氏COMBAS AmpliPrep／COMBAS TaqMan HIV—1 Test version 2．0（简称TagMan v2．0试剂）和生物梅里埃NucliSENS EasyQ HIV-1 v2．0（简称EasyQ v2．0试剂）两种试剂,检测艾滋病病毒Ⅰ型（HIV-1）病毒载量间的相关性和一致性。方法 对40份血浆样本采用TaqMan EasyQ v2．0试剂和EasyQ v2．0试剂分别检测HIV-1病毒载量。统计学处理采用配对t检验、回归分析和Bland—Altman分析。结果TaqMan v2．0和EasyQ v2．0试剂测得的病毒载量均值分别为（4．41±0．72）log10拷贝／mL和（3．75±0．75）log10拷贝／mL,差异有统计学意义（t=10．441,P〈0．001）。对两种试剂的检测结果进行回归分析表明,两种试剂有较强的相关性（R2=0．817）。用Bland—Altman分析比较两种试剂检测结果的差异均值,结果具有较好的一致性。结论TaqMan v2．0和EasyQ v2．0两种试剂盒在检测HIV-1病毒载量时具有较好的相关性和一致性。