Limited Impact of the Thymus on Immunological Recovery During and After Chemotherapy in Patients with Diffuse Large B-cell Lymphoma

To investigate the impact of thymus on immunological recovery after dose-dense chemotherapy a prospective study of 17 patients diagnosed with diffuse large B-cell lymphoma (DLBCL) was conducted. Patients were monitored before, during and until 3 months after chemotherapy. The thymus was visualized using computer tomographic scans. Patients were divided into two groups according to thymic size, one group comprising of patients without detectable thymus and one group of patients with detectable thymus. Naïve CD4 and CD8 counts were measured by flow cytometry, and to measure thymic output determination of CD4+ cells containing T-cell receptor excision circles (TREC) was done. During chemotherapy, the naïve CD4 count decreased significantly as did the CD4-TREC%. Significant difference in recovery of naïve CD4 counts between patients with detectable and undetectable thymic tissue during treatment with chemotherapy was not found. CD4-TREC% was associated with lower age. It was not possible to demonstrate an association between thymic size and recovery of the naïve CD4+ cells. The study terminated 3 months after the last cycle of chemotherapy, and at that time point the naïve CD4 counts and the CD4-TREC% had not returned to pretreatment levels. However, patients with detectable thymic tissue had higher naïve CD4 counts after the first cycles of chemotherapy, suggesting that these patients may be less susceptible to infectious complications related to chemotherapy.     

Changes in thymus volume in adult HIV-infected patients under HAART: correlation with the T-cell repopulation

An important thymus role has been suggested in T‐cell repopulation after HAART in adult HIV‐1 infected patients. Thymus volume increase after treatment has been described in HIV‐1 infected children but not in adult patients. The objective of this work was to evaluate the effect of HAART on the thymic volume of adult HIV‐1 infected patients and its relation with the T‐cell repopulation. Twenty‐one adult patients following 24 weeks under HAART were included in the study. All patients underwent a thoracic computed tomography (CT) evaluation for the measurement of thymic volumes at weeks 0, 12 and 24. Baseline thymus volume showed a significant correlation with the patient's age. Thymic volume significantly increased after 24 weeks of HAART. Besides, a significant correlation between changes in the thymus volume and changes in both total and naïve CD4+ cell counts was found. Only patients with increases ≥100 CD4+ cell counts after treatment significantly increased the thymic volume. These data show the first evidence of an early change in thymic volume of adult HIV‐1 infected patients under HAART. This increase was related to the rise of both total and naïve CD4+ cell counts suggesting a functional role of thymic volume increase.     

HIV-infected children with moderate/severe immune-suppression: changes in the immune system after highly active antiretroviral therapy

The objective of this study was to monitor the changes in the immune system of HIV-infected children with moderate or severe immunodeficiency after highly active antiretroviral therapy (HAART), comprising a follow-up study in 14 HIV-infected children on HAART at two time points separated approximately by 11.8 +/- 0.4 (9.9; 15.4) months. HIV-infected children had significantly lower TREC levels than the control group, but 1 year after HAART the levels increased significantly (P < 0.05). In contrast, viral load (VL) did not change significantly. A positive correlation between T cell receptor excision circle (TREC) levels and both CD4(+) T cell absolute counts (r = 0.558; P = 0.05) and percentages (r = 0.625; P = 0.030) was found. During follow-up on HAART, the percentages and absolute counts of naive CD4(+) and CD8(+) T cell subsets were increased significantly (P < 0.05). CD4(+) CD45RA(hi+) CD62L(+), CD4(+) CD45RA(+) and CD4(+) CD38(+) percentages, and the CD8(+) CD45RA(hi+) CD62L(+) counts reached similar values to the control group. Also, CD8(+) CD45RO(+) CD38(+) and CD8(+) CD45RO(+) percentages, and CD8(+) CD45RO(+) CD38(+) absolute counts (P < 0.05) decreased with respect to the baseline. Lymphoproliferative responses to pokeweed mitogen (PWM) before HAART were lower in HIV-infected children than the control group, but they recovered to normal levels after a year on HAART. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma production by PHA-activated peripheral blood mononuclear cells (PBMC) was lower before HAART (P < 0.001), but reached similar levels to the control group 1 year after HAART. In HIV-infected children IgG, IgG(1) and IgG(3) plasma levels decreased significantly after HAART. The immune system reconstitution induced by HAART in HIV-infected children seems to be the consequence of decreased immune system activation and naive T cell reconstitution, mainly of thymic origin.     

Multiparameter evaluation of human thymic function: interpretations and caveats

After the provision of highly active antiretroviral therapy (HAART), the level of circulating CD4+ T cells increases in many adults infected with the human immunodeficiency virus, type 1 (HIV). To study factors involved in immune reconstitution, we have measured thymic abundance by CT scans, circulating naive-phenotype CD4+ T cells by flow cytometry, and T cell receptor (TCR) rearrangement excision circles (TRECs) by quantitative PCR in 40 virologically suppressed, HIV-infected adults and 33 age-matched, HIV-uninfected controls. In HIV-uninfected subjects, naive T cell numbers, thymic abundance, and the frequency of circulating naive CD4+ T cells bearing TRECs decreased with age, as expected. When corrected for this relationship with age, naive T cell numbers correlated significantly with naive T cell TREC frequencies. Virologically suppressed HIV-infected subjects had higher TREC frequencies, and subjects over the age of 39 were more likely to have abundant thymus compared to age-matched, HIV-uninfected adults. Nevertheless, all HIV-infected subjects had reduced absolute numbers of naive T cells, irrespective of thymic size, age, or TREC frequencies. These data illustrate the complex relationship between these measures of thymic size and function and underscore the need to develop more definitive measures of thymic function in the future.     

Thymic volume is associated independently with the magnitude of short- and long-term repopulation of CD4+ T cells in HIV-infected adults after highly active antiretroviral therapy (HAART)

Age is one of the main factors involved in the rapidity and the magnitude of CD4(+) T cell repopulation in human immunodeficiency virus (HIV)-infected patients on highly active antiretroviral treatment (HAART). Improved thymic function has been suggested as the main factor associated with CD4(+) T cell restoration after HAART. This work was undertaken to determine, among host factors, the predictor variable at baseline involved in the magnitude of short- and long-term recovery of CD4(+) T cells after HAART. HIV-RNA levels and CD4(+) T cell numbers were determined in 54 HIV-infected adults at baseline and at weeks 4, 12, 48 and 96 after HAART. T cell subpopulations were determined by flow cytometry, thymic volume by computed tomography, T cell receptor excision circle (TREC)-bearing cells by quantitative polymerase chian reaction (PCR) and interleukin (IL)-7 levels by enzyme linked immunosorbent assay at baseline. The phenotype of patients' isolates was determined by infecting GHOST cells expressing CCR5 and CXCR4. The possible interference of phenotype with thymic function was also analysed. Baseline thymic volume was associated independently with the magnitude of short- and long-term recovery of CD4(+) T cells after HAART, despite the patients' viral phenotype. The measurement of thymic volume before therapy may predict the magnitude of T cell increase. This result could have important clinical implications not only in HIV-infected patients, but also in other scenarios of T cell depletion such as bone marrow transplantation and chemotherapy.     

Herpes zoster in women with and at risk for HIV: data from the Women's Interagency HIV Study

BACKGROUND: Herpes zoster occurs at all CD4 cell counts in HIV-infected adults. It was hypothesized that even in the era of highly active antiretroviral therapy (HAART), zoster risk is higher in HIV-infected than uninfected women. METHODS: Generalized estimating equations modeled self-reported occurrence of zoster between semiannual visits among 1832 HIV-infected and 489 HIV-uninfected women in the Women's Interagency HIV Study followed for up to 7.5 years. RESULTS: A total of 337 (18.4%) HIV-infected and 7 (1.4%) HIV-uninfected women reported zoster at some time during follow-up. Using HIV-infected women with CD4 >750 cells/microL as the reference category, the odds ratios for reporting zoster since the prior visit were: 1.43 (95% CI 0.86-2.37) for CD4 500-749 cells/microL, 2.07 (95% CI 1.27-3.38) for CD4 350-499 cells/microL, 2.72 (95% CI 1.66-4.46) for CD4 200-349 cells/microL, and 3.16 (95% CI 1.92-5.18) for CD4 <200 cells/microL, compared with 0.11 (95% CI 0.046-0.26) for HIV-uninfected women. In multivariate analyses using visits from all HIV-infected women and only those who initiated HAART, lower CD4 cell count was more strongly associated with zoster incidence than were other clinical indicators. CONCLUSIONS: Herpes zoster is associated with degree of immunosuppression in HIV-infected women, but even women with high CD4 counts are at greater risk of zoster than HIV-uninfected women.     

Longer Duration of HBV-Active Antiretroviral Therapy is Linked to Favorable Virological Outcome in HIV-HBV Co-infected Patients

Abstract

Background: HBV-HIV co-infection is associated with increased liver-related morbidity and mortality. Herein we analyzed HBV-related virologic and clinical outcomes in HBV-HIV patients in the HAART era. Methods: HBsAg positive HIV-infected patients followed at a US academic center between 1990 and 2008 were assessed in a retrospective and longitudinal study. Factors associated with HBsAg and/or HBeAg clearance and with advanced liver disease were evaluated using logistic regression. Results: 72 patients were evaluated. Their median time of follow-up and of adherence to HBV-active HAART were 3 and 1 years, respectively. HBeAg and HBsAg cleared in 17.6% and 5.5% of patients, respectively. More prolonged use of HBV-active HAART predicted clearance of HBeAg (odds ratio [OR] 2.66, 95% CI 1.15–6.16, p = .02) and of HBsAg (OR 1.54, 95% CI 1.02–2.31, p = .04). Patients clearing HBsAg tended to have higher baseline CD4 (mean CD4 counts: 550 vs. 246 cells/mm³; p = .06). Rate of diagnosis of liver-related complications and death were 24.6/1,000 and 10.5/1,000 patient-years, respectively. Higher ALT levels before HAART initiation were associated with the diagnosis of cirrhosis during follow-up (OR 1.02, 95% CI 1.002–1.03, p = .02). Conclusions: Prolonged use of HBV-active HAART favors HBsAg and HBeAg clearance in HIV-HBV co-infected patients. Those with higher ALT levels at presentation have higher risk of being diagnosed with cirrhosis during the first few years of follow-up.     

Increases in CD4+ T lymphocytes occur without increases in thymic size in HIV-infected subjects receiving interleukin-2 therapy

OBJECTIVE: To examine the potential contribution of the thymus to CD4+ T-lymphocyte increases in HIV-infected patients receiving intermittent interleukin-2 (IL-2) therapy. DESIGN: Fifteen HIV-infected patients treated with antiretroviral regimens who were enrolled in a study of intermittent IL-2 therapy and were willing to undergo serial thymic computed tomography (CT) were prospectively studied. METHODS: Thymic CT was performed before and approximately 6 and 12-17 months after intermittent IL-2 therapy was started. Scans were graded in a blinded manner. Changes in lymphocyte subpopulations were determined by flow cytometry. RESULTS: Statistically significant increases in CD4+ T lymphocytes occurred with IL-2 administration, with a preferential increase in naive relative to memory CD4+ T cells. Despite this increase in naive CD4+ T cells, overall there was a modest decrease in thymic volume observed during the study period. No correlation was found between changes in thymic volume indices and total, naive, or memory CD4+ T-lymphocyte counts. CONCLUSIONS: These findings demonstrate that the profound CD4+ T-lymphocyte increases seen with intermittent IL-2 administration are not associated with increases in thymic volume and more likely are due to peripheral expansion rather than increased thymic output.     

Increased levels of regulatory T cells (Tregs) in human immunodeficiency virus‐infected patients after 5 years of highly active anti‐retroviral therapy may be due to increased thymic production of naive Tregs

This study determines levels of regulatory T cells (T_regs), naive T_regs, immune activation and cytokine patterns in 15 adult human immunodeficiency virus (HIV)‐infected patients receiving prolonged highly active anti‐retroviral therapy (HAART) who have known thymic output, and explores if naive T_regs may represent recent thymic emigrant T_regs. HIV‐infected patients treated with HAART with a median of 1 and 5 years were compared with healthy controls. Percentages of T_regs (CD3⁺CD4⁺CD25⁺CD127^low), naive T_regs (CD3⁺CD4⁺CD25⁺CD45RA⁺) and activation markers (CD38⁺human leucocyte antigen D‐related) were determined by flow cytometry. Forkhead box P3 mRNA expression and T cell receptor excision circles (T_REC) content in CD4⁺ cells were determined by polymerase chain reaction and cytokines analysed with Luminex technology. Levels of T_regs were significantly higher in HIV‐infected patients compared with controls, both after 1 and 5 years of HAART (P < 0·001), despite fully suppressed HIV‐RNA and normalization of both CD4 counts, immune activation and cytokine patterns. Furthermore, levels of naive T_regs were elevated significantly in HIV‐infected patients (P < 0·001) and were associated with thymic output measured as the T_REC frequency in CD4⁺ cells (P = 0·038). In summary, T_reg levels in HIV‐infected patients are elevated even after 5 years of HAART. Increased thymic production of naive T_regs may contribute to higher T_reg levels in HIV‐infection.     

Association of CD4+ T-lymphocyte counts and new thymic emigrants in HIV-infected children during successful highly active antiretroviral therapy

BACKGROUND: In a cohort of children receiving highly active antiretroviral therapy (HAART) with sustained plasma HIV-1 RNA < 50 copies/mL, children who reached undetectable RNA after week 8 (slow responders, median: week 20) had higher HIV-1 intracellular DNA (HIV-1 DNA) and equal or greater CD4+ T-lymphocyte counts compared with children who reached undetectable plasma HIV-1 RNA by week 8 (rapid responders) throughout HAART. OBJECTIVE: To determine whether levels of T-cell receptor excision circles (TRECs) could explain the apparent inconsistency between the quantity of HIV-1 DNA and CD4+ T-lymphocyte counts in HIV-1-infected children receiving HAART with sustained virologic suppression. METHODS: T-cell receptor excision circles and HIV-1 DNA and plasma HIV-1 RNA were quantified longitudinally by PCR in 31 children (median age, 5.6 years) with sustained undetectable plasma HIV-1 RNA for >104 weeks of HAART. RESULTS: There was a positive correlation between TREC and HIV-1 DNA during HAART, notably at weeks 48 and 80 (P < .004). During the early stage of HAART, TREC levels positively correlated with CD4+ T-lymphocyte percentages (P < .02) and naive CD4+ T-lymphocyte counts (P < .001) and percentages (P = .05). Median TREC levels were consistently equal or higher in slow responders compared with rapid responders (P < .001) despite slow responders having consistently greater quantities of HIV-1 DNA. CONCLUSION: To maintain adequate levels of CD4+ T-lymphocytes, children with high HIV-1 DNA maintain high levels of TREC while receiving HAART. Thus, a thymic control mechanism is required to maintain new CD4+ T lymphocytes in the presence of persistent virus. CLINICAL IMPLICATIONS: The TREC level is a useful marker of thymic function in HIV-infected children.     

CD4 cell counts of 800 cells/mm3 or greater after 7 years of highly active antiretroviral therapy are feasible in most patients starting with 350 cells/mm3 or greater

OBJECTIVE: CD4 cell count changes in therapy-naive patients were investigated during 7 years of highly active antiretroviral therapy (HAART) in an observational cohort. METHODS: Three endpoints were studied: (1) time to >or=800 CD4 cells/mm in 5299 therapy-naive patients starting HAART, (2) CD4 cell count changes during 7 years of uninterrupted HAART in a subset of 544 patients, and (3) reaching a plateau in CD4 cell restoration after 5 years of HAART in 366 virologically suppressed patients. RESULTS: Among patients with <50, 50 to 200, 200 to 350, 350 to 500, and >or=500 CD4 cells/mm at baseline, respectively, 20%, 26%, 46%, 73%, and 87% reached >or=800 CD4 cells/mm within 7 years of starting HAART. Periods with HIV RNA levels >500 copies/mL and age >or=50 years were associated with lesser increases in CD4 cell counts between 6 months and 7 years. Having reached >or=800 CD4 cells/mm at 5 years, age >or=50 years, and >or=1 HIV RNA measurement >1000 copies/mL between 5 and 7 years were associated with a plateau in CD4 cell restoration. CONCLUSIONS: Restoration to CD4 cell counts >or=800 cells/mm is feasible within 7 years of HAART in most HIV-infected patients starting with >or=350 cells/mm and achieving sufficient suppression of viral replication. Particularly in patients >or=50 years of age, it may be beneficial to start earlier than current guidelines recommend.     

Immunogenicity of 23-valent pneumococcal polysaccharide vaccine in children with human immunodeficiency virus undergoing highly active antiretroviral therapy.

BACKGROUND: The 23-valent pneumococcal polysaccharide vaccine (23PSV) has been recommended for children infected with human immunodeficiency virus (HIV); however, the efficacy of this vaccination in HIV-infected children undergoing highly active antiretroviral therapy (HAART) has not been studied. OBJECTIVE: To study the immunogenicity and immunologic protection of 23PSV in HIV-infected children after stable HAART. METHODS: Serotype-specific IgG antibodies to 12 pneumococcal capsular polysaccharides were analyzed before and after 23PSV vaccination in 41 HIV-infected children undergoing HAART and compared with 95 HIV-negative control children. Seropositivity, clinical protection, and additional clinical protection from 23PSV were calculated based on serotype specific IgG antibody levels and on the known incidence of these serotypes for causing invasive disease. RESULTS: Children with HIV infection undergoing HAART developed a significant increase in specific IgG levels to Streptococcus pneumoniae after 23PSV vaccination (0.95 vs 1.84 micro/gmL, P < .001). The HIV-infected children with CD4+ cell counts of 25% or higher at the time of vaccination developed a higher additional clinical protection gain from 23PSV vaccination than did children with a lower percentage of CD4+ cells. CONCLUSIONS: HIV-infected children undergoing stable HAART develop a significant immunologic response to 23PSV, especially those with higher T-cell counts and lower viral loads at the time of vaccination.     

Impact of weight on immune cell counts among HIV-infected persons

Prior studies have shown that weight may impact immune cell counts. However, few data exist about the relationship of weight and immune cell counts among HIV-infected patients. We examined documented HIV seroconverters (mean window, 15.7 months) in a prospective U.S. Military HIV Natural History Study (1 January 1986 to 20 January 2010). We estimated the association of the time-updated body mass index (BMI) category with changes in immune cell counts from HIV diagnosis across time (mean follow-up of 5.1 years) using multiply adjusted longitudinal linear mixed-effects models. Of 1,097 HIV seroconverters, 448 (41%) were overweight and 93 (8%) were obese at HIV diagnosis. Immune cell counts at HIV diagnosis did not significantly differ by BMI category. In the longitudinal models for those diagnosed before the advent of the highly active antiretroviral therapy (HAART) era, mean postdiagnosis decreases in the white cell count, total lymphocyte count, CD4 count, CD4 percentage, and CD4/CD8 ratio were less as the BMI category increased (all with P values of <0.05). Among HIV seroconverters diagnosed in the HAART era, obese compared to normal-weight patients had significantly smaller increases in CD4 counts, CD4 percentages, and the CD4/CD8 ratio (all with P values of <0.05). Similar findings were also noted among underweight versus normal-weight patients. In conclusion, although BMI was not associated with immune cell levels at the time of HIV diagnosis, weight appears to affect immune cells counts over the course of infection. In the HAART era, being either underweight or obese was associated with smaller increases in several important immune cell levels, including the CD4/CD8 ratio.     

TTV Viral Load As a Marker for Immune Reconstitution After Initiation of HAART in HIV-Infected Patients

Abstract

Purpose: To investigate whether TT virus (TTV) viral load may be used as a surrogate marker for functional immune reconstitution in HIV-infected patients receiving highly active antiretroviral therapy (HAART). Method: Fifteen protease inhibitor-naÏve HIV-infected patients were included in a longitudinal study. From each patient, three serum samples taken before HAART initiation and three samples taken during HAART were analyzed. TTV was detected by polymerase chain reaction (PCR) and was quantitated by competitive PCR. TTV viral heterogeneity was determined by restriction fragment length polymorphisms (RFLPs) and sequencing. Results: All 15 HIV-infected patients were TTV positive. No significant change in HIV RNA or TTV viral load was observed at the three time points before HAART initiation. Even though HAART lead to an immediate and significant reduction in HIV RNA (p = .0001), a significant reduction in TTV viral load (p = .0002) was not observed until after 3-5 months of HAART. Four patients did not have an increase in CD4+ T cell count after 1 year of HAART; however, a decrease in TTV viral load was still observed, and three of these patients had a reduction in HIV RNA. RFLPs and sequencing revealed that TTV is represented as a heterogeneous population of virus in HIV-infected patients. Conclusion: This pilot study suggests that HAART leads to improved immunological responses, even in patients who do not have an increase in CD4+ T cell counts. We propose that the change in TTV viral load may be useful in the evaluation of cellular immune response at a functional level in HIV-infected patients who receive HAART.     

Impaired Recovery of CD4+ Cell Counts Following Highly Active Antiretroviral Therapy in Drug-Naïve Patients Coinfected with Human Immunodeficiency Virus and Hepatitis C Virus

Coinfection with the human immunodeficiency virus (HIV) and the hepatitis C virus (HCV) is highly prevalent in southern Europe. However, there are few and contradictory data about the effect of HCV carriage on the response to highly active antiretroviral therapy (HAART). In this study, the recovery of CD4+ T cells following HAART among antiretroviral-naïve patients seropositive for HIV with and without HCV coinfection was investigated. Two hundred one HIV-infected patients without previous exposure to antiretroviral drugs were included in the study. HCV coinfection was detected in 123 (61%) patients. The time to recover 200 CD4+ cells/µl was longer in the HCV-positive group (P<0.001). In a Cox model, HCV infection and lack of persistent HIV viremia (defined as <200 copies/ml) were associated with the time to recover 200 CD4+ cells/µl. The mean increase in CD4+ cell counts was lower in the HCV-positive group during the first year of therapy. HIV/HCV-coinfected patients naïve for antiretroviral therapy show a delayed recovery of CD4+ cell counts after starting HAART.     

Cognitive functioning in school-aged children with vertically acquired HIV infection being treated with highly active antiretroviral therapy (HAART)

In today's era of highly active antiretroviral therapy (HAART), few children with HIV-1 infection experience severe central nervous system (CNS) manifestations indicative of encephalopathy. However, little is known about the neurocognitive strengths and weaknesses of HIV-infected children treated with HAART. This cross-sectional study is the first to systematically investigate the relation between cognitive functioning and medical markers in HIV-infected children and adolescents treated with HAART with varying levels of computed tomography (CT) brain scan abnormalities. The Wechsler Intelligence Scale for Children-Third Edition was administered to 41 vertically infected children (mean age = 11.2 years) treated with HAART for at least 1 year. Other procedures at the time of testing included CT brain scans and collection of CD4 cell counts and plasma HIV-1 RNA PCR. Although global cognitive functioning among participants was in the Average range, children with minimal to moderate CT brain scan abnormalities scored significantly lower than children with normal scans on composite measures of cognitive functioning and five specific subtests, especially tasks involving executive functions. Furthermore, children with worse immune status (CD4+ counts ≤ 500) scored lower on subtests measuring processing speed. Viral load was unrelated to cognitive test scores. Thus, children with HIV being treated with HAART remain at risk for developing CNS disease. Findings emphasize the importance of conducting neuropsychological assessments in this population, particularly for children with cortical atrophy and absolute CD4+ cell counts ≤ 500.     

Excess apoptosis of mononuclear cells contributes to the depressed cytomegalovirus-specific immunity in HIV-infected patients on HAART

HIV-infected patients on highly active antiretroviral therapy (HAART) have persistently decreased cytomegalovirus (CMV)-specific proliferative responses [lymphocyte proliferation assay (LPA)] in spite of increases in CD4+ T cell counts. Here we demonstrate an association between apoptosis of unstimulated peripheral blood mononuclear cells (uPBMC) and decreased CMV-LPA. HAART recipients had more apoptosis of uPBMC than controls when measured by caspases 3, 8, and 9 activities and by annexin V binding. Patients with undetectable HIV replication maintained significantly higher apoptosis of CD4+ and CD14+ cells compared to controls. CMV-LPA decreased with higher apoptosis of uPBMC in patients only. This association was independent of CD4+ cell counts or HIV replication. Furthermore, rescuing PBMC from apoptosis with crmA, but not with TRAIL- or Fas-pathway blocking agents or with other caspase inhibitors, increased CMV-LPA in HAART recipients. This effect was not observed in uninfected controls, further indicating that the down regulatory effect of apoptosis on cell-mediated immunity (CMI) was specifically associated with the HIV-infected status.     

Mortality in the highly active antiretroviral therapy era: changing causes of death and disease in the HIV outpatient study

BACKGROUND: AIDS-related death and disease rates have declined in the highly active antiretroviral therapy (HAART) era and remain low; however, current causes of death in HAART-treated patients remain ill defined. OBJECTIVE: To describe mortality trends and causes of death among HIV-infected patients in the HAART era. DESIGN: Prospective, multicenter, observational cohort study of participants in the HIV Outpatient Study who were treated from January 1996 through December 2004. MEASUREMENTS: Rates of death, opportunistic disease, and other non-AIDS-defining illnesses (NADIs) determined to be primary or secondary causes of death. RESULTS: Among 6945 HIV-infected patients followed for a median of 39.2 months, death rates fell from 7.0 deaths/100 person-years of observation in 1996 to 1.3 deaths/100 person-years in 2004 (P=0.008 for trend). Deaths that included AIDS-related causes decreased from 3.79/100 person-years in 1996 to 0.32/100 person-years in 2004 (P=0.008). Proportional increases in deaths involving liver disease, bacteremia/sepsis, gastrointestinal disease, non-AIDS malignancies, and renal disease also occurred (P=or<0.001, 0.017, 0.006, <0.001, and 0.037, respectively.) Hepatic disease was the only reported cause of death for which absolute rates increased over time, albeit not significantly, from 0.09/100 person-years in 1996 to 0.16/100 person-years in 2004 (P=0.10). The percentage of deaths due exclusively to NADI rose from 13.1% in 1996 to 42.5% in 2004 (P<0.001 for trend), the most frequent of which were cardiovascular, hepatic, and pulmonary disease, and non-AIDS malignancies in 2004. Mean CD4 cell counts closest to death (n=486 deaths) increased from 59 cells/microL in 1996 to 287 cells/microL in 2004 (P<0.001 for trend). Patients dying of NADI causes were more HAART experienced and initiated HAART at higher CD4 cell counts than those who died with AIDS (34.5% vs 16.8%, respectively, received HAART for 4 of more years, P<0.0001; 22.4% vs 7.8%, respectively, initiated HAART with CD4 cell counts of more than 350 cells/microL, P<0.001). CONCLUSIONS: Although overall death rates remained low through 2004, the proportion of deaths attributable to non-AIDS diseases increased and prominently included hepatic, cardiovascular, and pulmonary diseases, as well as non-AIDS malignancies. Longer time spent receiving HAART and higher CD4 cell counts at HAART initiation were associated with death from non-AIDS causes. CD4 cell count at time of death increased over time.     

Differential upregulation of CD38 on different T-cell subsets may influence the ability to reconstitute CD4+ T cells under successful highly active antiretroviral therapy

BACKGROUND: Immune activation is an independent surrogate marker of CD4 T-cell depletion in HIV-infected patients. Highly active antiretroviral therapy (HAART) reduces disease progression as a direct consequence of suppressing HIV replication. Immune function does not normalize completely in most subjects on HAART, however, perhaps reflecting residual HIV replication. So far, it is unclear to what extent immune activation may influence the evolution of CD4 T-cell counts in patients on HAART. PATIENTS AND METHODS: The expression of CD38 on naive and memory subsets of CD4+ and CD8+ T cells was measured quantitatively by flow cytometry in 62 drug-naive HIV-positive and 30 HIV-uninfected controls. In addition, the evolution of this marker as well as that of some virologic parameters (plasma viremia and proviral load) and CD4 counts were assessed in 25 HIV-infected individuals who initiated HAART and were followed for 12 months. RESULTS: The mean level of CD38 on memory CD4+ and CD8+ T cells as well as in naive CD8+ cells was significantly higher in drug-naive HIV-positive subjects than in HIV-negative controls. Moreover, it was highly correlated with viral load titers. In patients on successful HAART, immune activation declined in all T-cell subsets, particularly among memory CD8+ cells. It remained elevated with respect to HIV-negative controls, however, even after 12 months of HAART. There was a significant correlation between the CD8+ T-cell activation decay and the increase of CD4+ T cells on HAART. Patients with the highest decline in CD8 activation were those showing the highest CD4 T-cell gains after 12 months of therapy. CONCLUSIONS: The level of CD38 expression on different T-cell subsets is differentially upregulated in drug-naive HIV-infected patients. After successful HAART, immune activation decreases in all T-cell subsets, although it still remains elevated in most cases after 12 months of HAART. The extent of immune deactivation under successful HAART correlates with the ability to reconstitute CD4 counts.     

Effect of clinical pharmacists on utilization of and clinical response to antiretroviral therapy

OBJECTIVE: To determine the association of clinical pharmacists with health outcomes and utilization measures among HIV-infected patients. METHODS: Observational study of 1571 HIV-infected patients prescribed their initial highly active antiretroviral therapy (HAART) regimen in clinics with and without a clinical pharmacist. Outcomes analyzed were changes in plasma HIV RNA level, CD4 T-cell counts, and service utilization (hospital days, emergency department visits, and office visits) over 24 months based on exposure to a clinical pharmacist. RESULTS: Patients exposed to a clinical pharmacist tended to be more likely to achieve an HIV RNA level <500 copies/mL at 12 months (adjusted odds ratio [OR] = 2.01, 95% confidence interval [CI]: 0.92 to 4.37). At 24 months, however, results depended on the provider panel size; the ORs for panel sizes < or =50 and >50 HIV-infected patients were 1.67 (95% CI: 0.60 to 4.62) and 0.97 (95% CI: 0.39 to 2.41), respectively. CD4 T-cell counts were modestly but nonsignificantly higher for the patients exposed to a clinical pharmacist. Utilization also depended on the provider panel size; pharmacist exposure was associated with 64% (95% CI: 30% to 108%) and 9% (95% CI: -11% to 33%) increases in total hospital days for panel sizes < or =50 and >50 HIV-infected patients, respectively. Pharmacist exposure was also associated with a 19% (95% CI: -13% to -24%) decrease in office visits for panel sizes < or =50 HIV-infected patients, with minimal effect for larger panel sizes. CONCLUSION: Clinical pharmacists seem to contribute to lower office visit rates in antiretroviral-naive patients initiating HAART.