Reduced mobilization of CD34+ stem cells in advanced human immunodeficiency virus type 1 disease

Granulocyte colony-stimulating factor (r-met Hu G-CSF; filgrastim; 10 microgram/kg/day for 7 days) was used to mobilize CD34+stem cells into the peripheral blood of human immunodeficiency virus type 1 (HIV-1)-infected individuals and a group of HIV-1-uninfected donors as a measure of immunologic reserve in HIV-1-infected people. G-CSF mobilized CD34+ cells of HIV-1-infected individuals with cell counts >500 CD4+ cells/mm3, as well as in HIV-1-uninfected donors. In contrast, CD34 cell mobilization was significantly blunted in HIV-1-infected individuals with cell counts <500 CD4+ cells/mm3 (<200 cell days vs. >650 cell days, P<.0005, compared with the >500 CD4+ cell cohort). At least 1.75x10(7) CD34 cells were harvested by leukapheresis from patients in each study cohort. CD34+ cell viability and the ability to differentiate precursor cells into myeloid and erythroid progenitor cells were not affected by HIV-1 infection.     

Low CD4 T cell counts before HIV-1 seroconversion do not affect disease progression in Ethiopian factory workers

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1)-uninfected Ethiopians have lower CD4 T cell counts than do other populations in Africa and industrialized countries. We studied whether this unique immunological profile results in shorter survival times in HIV-1-infected Ethiopians. METHODS: Data from an open cohort study of 149 HIV-1-infected factory workers in Ethiopia for 1997-2002 were used. To estimate survival times, a continuous-time Markov model was designed on the basis of CD4 T cell counts and World Health Organization clinical staging. By use of a random-effects model, decline in CD4 T cell counts was compared between HIV-1-infected Ethiopian and Dutch individuals. RESULTS: Median survival times were in the range of 9.1-13.7 years, depending on the approach used. This range is similar to that for populations in industrialized countries before the advent of antiretroviral therapy. Ethiopians had a lower annual decline in CD4 T cell counts than did Dutch individuals, which remained when groups with similar CD4 T cell count categories were compared. Moreover, the slower decline in CD4 T cell counts was not due merely to lower HIV-1 RNA loads or an absence of syncytium-inducing/X4 HIV-1 subtype C strains in Ethiopians. CONCLUSIONS: Low baseline CD4 T cell counts do not imply shorter survival times in Ethiopians than in other populations, presumably because of a slower decline in CD4 T cell counts.     

No difference in in vitro susceptibility to HIV type 1 between high-risk HIV-negative Ethiopian commercial sex workers and low-risk control subjects

Host factors such as increased beta-chemokine production, HIV-1 coreceptor expression level, and HIV-1 coreceptor polymorphism have been thought to influence susceptibility to HIV-1 infection. To determine the protective role of these factors in Ethiopians who remained HIV-1 uninfected, despite multiple high-risk sexual exposures, we studied 21 Ethiopian women who had been employed as commercial sex workers (CSWs) for five or more years. The HIV-1-resistant CSWs were compared with low-risk age-matched female controls who had a comparable CD4+ cell percentage and mean fluorescence intensity (MFI). Genetic polymorphism in the CCR5, CCR2b, or SDF-1 genes appeared not to be associated with resistance in the Ethiopian CSWs. Expression levels of CCR5 and CXCR4 on naive, memory, and total CD4+ T cells tended to be higher in the resistant CSWs, while the production of beta-chemokines RANTES, MIP-1alpha, and MIP-1beta by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) was lower compared with low-risk HIV-1 negative controls. In vitro susceptibility of PHA-stimulated PBMCs to primary, CCR5-restricted, Ethiopian HIV-1 isolates was comparable between resistant CSWs and low-risk controls. In vitro susceptibility was positively correlated to CD4+ cell mean fluorescence intensity and negatively correlated to CCR5 expression levels, suggesting that infection of PBMCs was primarily dependent on expression levels of CD4 and that CCR5 expression, above a certain threshold, did not further increase susceptibility. Our results show that coreceptor polymorphism, coreceptor expression levels, beta-chemokine production, and cellular resistance to in vitro HIV-1 infection are not associated with protection in high-risk HIV-1-negative Ethiopian CSWs.     

Quantitative ex vivo analysis of functional virus-specific CD8 T lymphocytes in the blood and genital tract of HIV-infected women

BACKGROUND: CD8 T lymphocytes are important in HIV-1 control and mediate virus-specific immunity in the blood and genital tract. The induction and monitoring of mucosal CD8 cell responses will be an important component of HIV-1 vaccine trials, but information regarding the frequency, phenotype and function of genital tract CD8 cell responses is lacking. METHODS: Simultaneous blood and cervical cytobrush samples were obtained from 16 HIV-1-infected Kenyan sex workers. Epitope-specific CD8 T lymphocyte frequencies in the blood and genital tract were analysed after short-term peptide incubation and intracellular cytokine staining for interferon-gamma (IFN gamma). RESULTS: Cervical sampling resulted in adequate cell numbers for analysis in 10/16 women. Background IFN gamma production was higher in CD3+/CD8+ lymphocytes from the genital tract than from blood (0.48% versus 0.1%; P < 0.01). Responses to staphylococcal enterotoxin B were detected in cervical CD8 lymphocytes from 10/10 women, at a similar frequency to blood (16.7% in cervix and 13.3% in blood; P = 0.4). HIV-1-specific responses were detected the cervix of 8/10 women, with a trend to higher response frequencies in the genital tract than blood (2.1% versus 0.8%; P = 0.09). Co-expression of integrin CD103 (alpha E beta 7), a mucosal marker, was used to confirm the mucosal origin of cervical responses. CONCLUSIONS: Cytobrush sampling and intracellular cytokine staining is well suited to the analysis of cervical CD8 cell responses. The frequency of functional virus-specific CD3+/CD8+ T cells is similar in the genital tract and blood of HIV-1-infected women. The role of genital tract CD8 cell responses in HIV-1 control warrants further investigation.     

Natural history of primary Epstein-Barr virus infection in children of mothers infected with human immunodeficiency virus type 1

The natural history of Epstein-Barr virus (EBV) infection in 556 infants born to 517 human immunodeficiency virus (HIV) type 1-infected mothers was studied in a prospective, multicenter, cohort study. HIV-1-infected children had a cumulative EBV infection rate similar to HIV-1-uninfected children at age 3 years (77.8% vs. 84. 9%) but had more frequent oropharyngeal EBV shedding (50.4% vs. 28. 2%; P<.001). The probability of shedding decreased with longer time from EBV seroconversion and was similar to that of HIV-1-uninfected children 3 years after seroconversion. HIV-1-infected children identified as rapid progressors shed EBV more frequently than nonrapid progressors (69.4% vs.41.0%; P=.01). HIV-1-infected children with EBV infection had higher mean CD8 cell counts. EBV infection did not have an independent effect on mean CD4 cell counts, percent CD4, IgG levels, HIV-1 RNA levels, lymphadenopathy, hepatomegaly, or splenomegaly. Early EBV infection is common in children born to HIV-1-infected mothers. Children with rapidly progressive HIV-1 disease have more frequent EBV shedding.     

Relationship of CD4+ T cell counts and HIV type 1 viral loads in untreated, infected adolescents. Adolescent Medicine HIV/AIDS Research Network

The REACH Project (Reaching for Excellence in Adolescent Care and Health) of the Adolescent Medicine HIV/AIDS Research Network was designed as a study of an adolescent cohort composed of HIV-1-infected and -uninfected subjects. The goal of the analysis presented was to examine the relationship of CD4+ T cell counts and HIV-1 plasma viral loads in adolescents. The CD4+ T cell counts of 84 HIV+ subjects who were 13 to 19 years of age were measured at the clinical sites, using ACTG standardized techniques. HIV-1 viral loads in frozen plasma were determined by the NASBA/NucliSens assay at a central laboratory. Past and current treatment with antiretroviral drugs was determined by medical record abstraction and interview data. The slope of the line generated by regressing log10 HIV-1 RNA (copies/ml) versus CD4+ T cell counts of REACH subjects who are antiretroviral drug naive was negative and significantly different than zero. A negative association has also been reported for antiretroviral drug-naive, adult males in the Pittsburgh Men's Study, a component of MACS (Pitt-MACS) (Mellors J, et al.: Science 1996;272:1167). These data show that in adolescents, as in adults, HIV-1 RNA concentrations are correlated with corresponding absolute CD4+ T cell count. The slopes of the lines generated with data from each cohort were different (p = 0.003). In addition to age, there are sex and racial differences in the makeup of the two cohorts. Any or all of these differences may affect the slopes of the lines.     

Presence of hepatitis C virus (HCV) RNA in the genital tracts of HCV/HIV-1-coinfected women

BACKGROUND: Hepatitis C virus (HCV)-infected women--in particular, those coinfected with human immunodeficiency virus type 1 (HIV-1)--can transmit infection to their children and sex partners. METHODS: The present study was conducted to analyze the presence of HCV RNA in cervicovaginal lavage (CVL) fluid from 71 women (58 HCV/HIV-1-coinfected women and 13 HCV-infected, HIV-1-uninfected women) enrolled in the Women's Interagency HIV Study. RESULTS: HCV RNA was detected (by a commercial polymerase chain reaction assay) in CVL fluid from 18 (29%) of the HIV-1-infected women and from none of the HIV-1-uninfected women (P<.05). Multivariate analysis revealed that risk factors for the presence of HCV RNA in CVL fluid were HCV viremia (odds ratio [OR], 16.81; P=.02) and HIV-1 RNA in CVL fluid (OR, 19.87; P=.02). This observation suggests local interactions between HIV-1 and HCV in the genital tract compartment. There was no correlation between HCV RNA in CVL fluid and CD4, CD8, or CD3 cell counts, HIV-1 RNA viremia, the number of leukocytes in CVL fluid, or HIV-1 therapy. Furthermore, in 3 of 5 analyzed patients who had a detectable CVL HCV RNA load, we found viral variants differing in the 5' untranslated region that were present neither in plasma nor in peripheral-blood mononuclear cells. CONCLUSIONS: Our observations point to the importance of the genital tract compartment, in which local HCV replication could be facilitated by local HIV-1 replication.     

Proliferative responses to human immunodeficiency virus type 1 (HIV-1) antigens in HIV-1-infected patients with immune reconstitution

Cell-mediated immunity is affected early in human immunodeficiency virus type 1 (HIV-1) infection. HIV-1-specific CD4+ T cell proliferative responses are not measurable in most patients but have been reported in long-term nonprogressors and in patients treated with highly active antiretroviral therapy (HAART) during primary infection. However, treatment with HAART generally does not restore HIV-1-specific CD4+ T cell responses in chronically infected patients. In this study, HIV-1-specific CD4+ T cell responses in 10 HIV-1-infected patients who began HAART with low CD4 cell count nadirs and experienced significant immune reconstitution were studied. Surprisingly, 5 of these patients had proliferative responses to > or =1 HIV-1 gene product, compared with 0 of 8 chronically infected patients who started HAART when their CD4 cell counts were still relatively high. These results suggest that, in some patients with advanced HIV-1 infection, treatment with HAART can lead not only to significant increases in CD4 cell counts but also to the restoration of HIV-1-specific responses.     

Evidence of B cell clonal expansion in HIV type 1-infected patients.

HIV-1 infection results in a gradual decrease in CD4(+) T cell counts and progressive immune deficiency. Increased T cell turnover in HIV-1-infected patients, which can be interpreted as T cell clonal expansion, has been thought to be relevant to its pathogenesis. To investigate whether B cell clonal expansion also occurs in HIV-1-infected patients, we examined the expressed V(H)DJ(H) gene sequences of peripheral B cells in HIV-1-infected patients with hypergammaglobulinemia. Identical V(H)DJ(H) gene rearrangements with additional nucleotide differences in V(H) genes were analyzed as a marker of clonally related B cells. From healthy individuals and HIV-1-uninfected patients with hypergammaglobulinemia, clonally related B cells were detected in none of 10 (0%) and 2 of 10 (20%), respectively. No clonally related B cells were detected in any of the nine HIV-1-infected patients with detectable viral loads and normal Ig levels (0%). In contrast, from 9 of 14 HIV-1-infected patients with hypergammaglobulinemia (64%), clonally related B cells were detected. In addition, no HIV-1-infected patients who exhibited normal Ig levels after antiretroviral therapy had clonally related B cells. These findings suggest that B cell clonal expansion is present in HIV-1-infected patients with hypergammaglobulinemia.     

Association of T cell proliferative responses and phenotype with virus control in chronic progressive HIV-1 disease

The role of T cell immunity in virus control during chronic infection was examined in 79 human immunodeficiency virus type 1 (HIV-1)-infected subjects randomized to receive antiretroviral therapy. HIV-1 p24-specific responses were detected in 20% of the subjects at baseline, increasing to 28% of the subjects at weeks 16-24. Induction of virologic suppression was associated with lower plasma HIV-1 RNA levels and a higher percentage of Fas+ CD8+ T cells at baseline, whereas maintenance of suppression was associated with higher CD4+ T cell counts and, marginally, with a higher percentage of Fas+ CD4+ T cells at weeks 16-24. These findings indicate that Fas coexpression on T cells, in addition to plasma HIV-1 RNA levels and CD4+ T cell counts, may predict virologic outcome.     

Effect of hepatitis C virus (HCV) genotype on HCV and HIV-1 disease

The relationship between hepatitis C virus (HCV) genotype and HCV and human immunodeficiency virus (HIV) type 1 disease is not well defined. The present study analyzed data from a cohort of 207 HIV-1-infected and 126 HIV-1-uninfected children and adolescents with hemophilia who enrolled in the Hemophilia Growth and Development Study and were followed for 7 years. The mean HCV RNA level was higher in the participants in the HCV genotype 1 group than in the participants the HCV non-genotype 1 group, among both the HIV-1-infected (difference, +0.33 log(10) copies/mL; P=.038) and HIV-1-uninfected (difference, +0.59 log(10) copies/mL; P=.008) participants. Although HCV genotype was not associated with differences in HIV-1 RNA level, a significantly lower mean CD4(+) T cell count (difference, -127 cells/ microL; P=.026) and percentage of CD4(+) T cells (difference, -4.3%; P=.027) were observed in the participants in the HCV genotype 1 group, compared with those in the participants in the HCV non-genotype 1 group. In addition, the participants in the HCV genotype 1 group were at increased risk for progression to AIDS-related mortality (hazard ratio, 2.44; P=.037). The present study suggests that HCV infection and genotype may influence the natural history of HCV and HIV-1 disease.     

Quantitative and qualitative abnormalities in HIV-1-specific T cells

OBJECTIVE: To assess the characteristics of CD4 and CD8 T cells specific for HIV-1 and cytomegalovirus (CMV) antigens in untreated and treated HIV-1-infected patients. METHODS: Antigen-specific T cell frequencies were determined by flow cytometric detection of antigen-induced intracellular cytokines. RESULTS: In untreated patients, HIV-1-specific CD4 T cell counts in peripheral blood were less than one tenth of CMV-specific CD4 T cell counts, while the number of specific CD8 T cells was approximately the same for both HIV-1 and CMV. In patients treated with highly active antiretroviral therapy (HAART) for less than 1.5 years, HIV-1-specific CD4 and CD8T cell counts were significantly lower than those in untreated patients. Perforin expression in HIV-1-specific CD8 T cells was significantly lower than that in CMV-specific CD8 T cells. CONCLUSION: These data indicate that HIV-1-specific T cells in HIV-1-infected patients have quantitative and qualitative abnormalities.     

Macrophage-activating cytokines in human immununodeficiency virus type 1-infected and -uninfected patients with pulmonary tuberculosis

Tuberculosis (TB) is the most common opportunistic infection in human immunodeficiency virus type 1 (HIV-1)-infected patients globally and occurs throughout the course of HIV-1 disease. Here the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by peripheral blood mononuclear cells (PBMC) of HIV-1-infected versus -uninfected patients with newly diagnosed pulmonary TB (PTB) was compared. Findings were correlated with cytokine profiles, clinical presentation, and expression of inducible nitric oxide (iNOS). Most HIV-1/PTB patients with a CD4 cell count of 200-500 cells/microL had high IFN-gamma production and radiographic evidence of atypical PTB. Low IFN-gamma production and radiographic evidence of reactivated PTB characterized both HIV-1/PTB patients with a CD4 cell count >or=500 cells/microL and HIV-1-uninfected patients. TNF-alpha levels were similar in all HIV-1/PTB patients, regardless of CD4 cell count. Induction of iNOS in PBMC was low and was associated with low IFN-gamma production. These data underscore the potential pathogenic role of macrophage-activating cytokines in TB in HIV-1-infected patients.     

Human immunodeficiency virus Type 1 (HIV-1) plasma virus load and markers of immune activation among HIV-infected female sex workers with sexually transmitted diseases in Abidjan, Côte d'Ivoire

Plasma levels of human immunodeficiency virus type 1 (HIV-1) RNA and markers of immune activation were compared among HIV-1-infected female sex workers (FSWs) with (n=112) and without (n=88) sexually transmitted diseases (STDs) in Abidjan, C?te d'Ivoire. After adjustment for CD4+ T cells, the median virus load was 2.5-fold higher among HIV-seropositive FSWs with STDs than among those without an STD (P=.053). Median virus load was higher for FSWs with a genital ulcer (P=.052) or gonorrhoea (P=.058) than for FSWs without any STD. Median levels of markers of immune activation (CD38 and HLA-DR on CD8+ T cells, soluble tumor necrosis factor-alpha receptor II, and beta(2)-microglobulin) tended to be elevated, albeit nonsignificantly, among FSWs in the STD group. These findings have important public health implications in elaborating strategies for decreasing disease progression and transmission of HIV among FSWs.     

Intravenous immunoglobulin (IVIG) treatment for modulation of immune activation in human immunodeficiency virus type 1 infected therapy-naive individuals

We evaluated the ability of intravenous immunoglobulin (IVIG) to diminish immune hyperactivation, which is considered a major cause of CD4+ T cell loss during chronic HIV-1 infection and whether this affected CD4+ T cell counts and plasma HIV-1 RNA (pVL). Therefore, we treated six chronically HIV-1-infected, antiretroviral-therapy-naive patients with IVIG (0.4 g/kg) at weeks 0 and 4, with a follow-up of 12 weeks after the second dosage during which pVL, T cell numbers, and T cell activation were measured. At baseline median CD4+ T cell counts were 300 (range 200-460) x 10(6)/liter and median pVL was 5.0 (range 3.2-5.2) log10 copies/ml. IgG plasma levels peaked during the first days after administration. We observed a decrease in the percentage of activated (CD38+ HLA-DR+) CD4+ and CD8+ T cells [3.5% (range 1-7%) and 5% (1-10%), respectively (p = 0.027)], but no effect on the fraction of proliferating CD4+ or CD8+ T cells as measured by Ki67 expression. CD4+ T cell counts were significantly increased on day 4 (median +55 cells, range 0-150, p = 0.043). pVL was significantly increased on day 1 after IVIG infusion (median +0.13 log10, range 0.01-0.55, p = 0.028). All these parameters returned to baseline levels within 1 week after infusion. In conclusion, administration of IVIG caused a temporary decrease in T cell activation and an increase in CD4+ T cell counts, despite an increase in pVL. Our results support the hypothesis that T cell activation, rather than direct HIV-1 infection, mediates the loss of CD4+ T cells and suggest that immunomodulating therapy in HIV-1 infection could indeed be effective.     

Effect of long-term infection with nef-defective attenuated HIV type 1 on CD4+ and CD8+ T lymphocytes: increased CD45RO+CD4+ T lymphocytes and limited activation of CD8+ T lymphocytes

Members of the Sydney Blood Bank Cohort (SBBC) have been infected with an attenuated strain of HIV-1 with a natural nef/LTR mutation and have maintained relatively stable CD4+ T lymphocyte counts for 14-18 years. Flow cytometric analysis was used to examine the phenotype of CD4+ and CD8+ T lymphocytes in these subjects, including the immunologically important naive (CD45RA+CD62L+), primed (CD45RO+), and activated (CD38+HLA-DR+ and CD28-) subsets. The median values were compared between the SBBC and control groups, comprising age-, sex-, and transfusion-matched HIV-1-uninfected subjects; transfusion-acquired HIV-1-positive LTNPs; and sexually acquired HIV-1-positive LTNPs. Members of the SBBC not only had normal levels of naive CD4+ and CD8+ T lymphocytes, but had primed CD45RO+ CD4+ T lymphocytes at or above normal levels. Furthermore, these primed cells expressed markers suggesting recent exposure to specific antigen. SBBC members exhibited variable activation of CD8+ T lymphocytes. In particular, SBBC members with undetectable plasma HIV-1 RNA had normal levels of activated CD8+ T lymphocytes. Therefore, the result of long-term infection with natural nef/LTR mutant HIV-1 in these subjects suggests a decreased cytopathic effect of attenuated HIV-1 on susceptible activated CD4+ T lymphocyte subsets in vivo, and minimal activation of CD8+ T lymphocytes.     

Successful HAART is associated with high B-chemokine levels in chronic HIV type 1-infected patients

Chemokine receptors are used by HIV-1 for entry into CD4+ T cells. The beta-chemokines are capable of inhibiting HIV replication. This study measured beta-chemokine macrophage inflammatory protein (MIP)-1alpha and MIP-1beta levels and determined the CCR5 and CXCR4 expression on T cells in HIV-1-infected patients treated with HAART. The time of known HIV infection and time of HAART use were similar between failure and successful groups. The CD4+ T cell nadir was 163 vs. 251 cells/mm3, p = 0.07, for failure and successful groups, respectively. The successfully treated group, when compared with the failure group, had a higher median CD4+ T cells count (667 vs. 257 cells/mm3; p = 0.003) as well as higher spontaneous MIP-1alpha (median of 4390 vs. 802 pg/ml, p = 0.03) and MIP-1beta (median of 2416 vs. 1117 pg/ml, p = 0.001) levels. The untreated patients had a higher number and intensity of CCR5- and CXCR4-expressing T cells. Higher levels of chemokines were not related to nadir CD4+ T and current CD8+ T cell counts. Successfully treated patients were able to produce higher amounts of beta-chemokines and normalize the coreceptor overexpression on T cells. These findings may have clinical implications, such as a new strategy of using chemokines as adjuvants in anti-HIV therapy.     

Normalization of CD4+ cell numbers and reduced levels of memory CD8+ cells in blood and tonsillar tissue after highly active antiretroviral therapy in early HIV type-1 infection

Antiretroviral therapy increases the number of both CD4+ and CD8+ T cells in the blood of HIV-1-positive patients with advanced disease. In the present study, we have examined the kinetics of CD4+ and CD8+ T cell restoration in blood and lymphoid tissue in asymptomatic HIV-1-positive individuals with high CD4+ cell counts during highly active antiretroviral treatment. Tonsillar biopsies and blood samples were collected at baseline and at regular intervals during the following 48 weeks and from HIV-1-negative controls. Mononuclear cells from blood and tonsils were phenotyped and quantified by three-color flow cytometry. After 48 weeks of therapy, blood CD4+ cell counts in the HIV-1-infected group were comparable to those found in uninfected controls. Naive CD4+ T cells in blood increased during the initial 2 weeks in parallel with reduced plasma viremia. Both naive and memory CD4+ T cells in blood reached normal numbers by week 48, whereas the CD4+ naive/memory cell ratio in tonsils was within normal range throughout the study. The level of memory CD8+ T cells in blood declined during the first 8 weeks in parallel with a reduction in the tonsillar memory CD8+ T cells. Naive CD8+ T cells in the blood increased after 4 weeks, while the level of naive CD8+ T cells in tonsils remained unaltered. Our data indicate that in the early stages of HIV-1 infection antiretroviral therapy normalizes CD4+ cell counts and causes a decrease in the level of memory CD8+ cells in blood and lymphoid tissue, suggesting reduced CD8+ cell turnover in response to reduced viral replication.