Suboptimal Immune Recovery Research Articles

Suboptimal immune recovery and associated factors among people living with HIV/AIDS on second-line antiretroviral therapy in central China: A retrospective cohort study.

The introduction and scale-up of antiretroviral therapy (ART) have contributed to significantly improved patients with acquired immune deficiency syndrome (AIDS) quality of life and prolongs their survival. This has occurred by suppressing viral replication and recovering the CD4 cell count. However, some patients do not normalize their CD4 cell count, despite suppression of the viral load (VL). Patients with suboptimal immune recovery (SIR), as defined by a VL < 400 copies/ml with a CD4 cell count of<200 cells/μl, after ART initiation, exhibit severe immune dysfunction and have a higher risk of AIDS and non-AIDS events. In recent years, People living with HIV/AIDS (PLWHA) with first-line ART failure began to gradually switch to second-line ART. This study aimed to examine the prevalence and factors affecting SIR among PLWHA who switch to second-line ART in rural China. A 1-year retrospective cohort study was conducted among PLWHA who switched to second-line ART between January 2009 and December 2018. All patients with a VL < 400 copies/ml after 1 year of second-line ART were included. SIR was defined as a CD4 cell count <200 cells/μl and a VL < 400 copies/ml after 1 year of second-line ART. The data collected from medical records were analyzed by univariate and multivariate analyses. A total of 5294 PLWHA met the inclusion criteria, 24 died, and 1152 were lost to follow-up after 1 year of second-line ART. Among 4118 PLWHA who were followed up, 3039 with a VL < 400 copies/ml had their data analyzed, and the prevalence of SIR was 13.1%. The patients' mean age at recruitment was 47.6 ± 8.1 years and 45.3% were men. A total of 30.7% of patients were HIV-positive for >8 years and 88.2% were receiving ART before starting second-line ART for >3 years. The mean CD4 cell count was 354.8 ± 238.2 cells/μl. A multivariable analysis showed that male sex, single status (unmarried or divorced), and a low CD4 cell count were risk factors for SIR among PLWHA with second-line ART. The prevalence of SIR among PLWHA who switched to second-line ART in this retrospective cohort study is lower than that in most other studies. Several factors associated with SIR include male sex, marital status, and CD4 cell count levels in PLWHA.

The Prevalence of HIV-infected Patients with Virological Suppression but a CD4+ T-cell Count of ≤ 200 Cells/mm3 after Highly Active Antiretroviral Therapy Initiation: A Meta-analysis.

Highly active antiretroviral therapy (HAART) strongly inhibits HIV replication. However, many patients show suboptimal immune recovery (SIR), as defined by virological suppression (i.e. low viral load) with a CD4+ T-cell count of ≤ 200 cells/mm3, after HAART initiation. Here, we performed a systematic evaluation of the SIR prevalence among HIV-infected patients in cohort studies. We searched PubMed, Cochrane Library, Embase, CNKI, Wanfang database, and Chinese Biomedicine Database for cohort studies about HIV-infected participants whose CD4+ T-cell count was ≤ 200 cells/mm3 but still had virological suppression after HAART initiation. The SIR prevalence from each of those cohort studies was pooled into a random-effect meta-analysis. We obtained two kinds of pooled post-HARRT initiation SIR prevalence: one among participants with virological suppression (11 cohort studies involving 18,672 participants), and the other among all HIV-infected participants (seven cohort studies involving 12,063 participants). The pooled SIR prevalence among HIV-infected patients with virological suppression after HAART initiation was 43% (95% confidence interval [CI], 34-51%) at 6 months post-HAART initiation and 10% (95% CI, 5-18%) at 36 months post-HAART initiation; among all HIV-infected patients after HAART initiation, it was 17% (95% CI, 0-55%) and 5% (95% CI, 2-10%) at 6 and 36 months post-HAART initiation, respectively. The SIR prevalence among HIV-infected patients is high at 6 months post-HAART initiation, but its prevalence gradually reduces over time under continuous HAART. Thus, it is important to follow-up on variations in the CD4+ T-cell count and viral load.

Determinants of suboptimal immune recovery among a Chinese Yi ethnicity population with sustained HIV suppression

ObjectivesDespite sustained viral suppression with effective antiretroviral therapy (ART), HIV-infected patients with suboptimal immune recovery are still at high risk of both non-AIDS-related and AIDS-related events. The aim of this study was to investigate determinants potentially associated with suboptimal CD4 + T cell count recovery during free ART with sustained viral suppression among an HIV-infected Yi ethnicity population in Liangshan Prefecture, an area in China with high HIV prevalence.MethodsThis retrospective study included HIV-infected Yi adults (≥ 18 years and baseline CD4 + T cell count less than 500 cells/μL) for whom ART supported by National Free Antiretroviral Treatment Program was initiated between January 2015 and December 2018 in Zhaojue County, Liangshan Prefecture. Virological suppression (viral load < 50 copies/mL) was achieved within 12 months after ART initiation, and sustained virological suppression was maintained. Multivariate log-binomial regression analysis was used to assess determinants of suboptimal immune recovery.ResultsThere were 140 female and 137 male patients in this study, with a mean age of 36.57 ± 7.63 years. Most of the Yi patients were infected through IDU (48.7%) or heterosexual contact (49.8%), and the anti-HCV antibody prevalence was high (43.7%, 121/277). Of the 277 patients with a mean ART duration of 3.77 ± 1.21 years, complete immune recovery occurred in only 32.9%. The baseline CD4 + T cell count in patients with suboptimal and intermediate immune recovery was 248.64 ± 108.10 and 288.59 ± 108.86 cells/μL, respectively, which was much lower than the baseline 320.02 ± 123.65 cells/μL in patients who achieved complete immune recovery (p < 0.001). Multivariable analysis demonstrated that low pre-ART CD4 + cell count and coinfection with HCV were associated with immune recovery of the HIV patients.ConclusionsOur study suggests that for HIV-infected Yi patients in Liangshan Prefecture, prompt ART initiation after diagnosis of HIV infection should be applied, and curative HCV treatment should be given to patients with HCV/HIV coinfection to improve the immunological effectiveness of ART.Trial registration None

Metabolite and thymocyte development defects in ADA-SCID mice receiving enzyme replacement therapy

Deficiency of adenosine deaminase (ADA, EC3.5.4.4), a housekeeping enzyme intrinsic to the purine salvage pathway, leads to severe combined immunodeficiency (SCID) both in humans and mice. Lack of ADA results in the intracellular accumulation of toxic metabolites which have effects on T cell development and function. While untreated ADA-SCID is a fatal disorder, there are different therapeutic options available to restore ADA activity and reconstitute a functioning immune system, including enzyme replacement therapy (ERT). Administration of ERT in the form of pegylated bovine ADA (PEG-ADA) has proved a life-saving though non-curative treatment for ADA-SCID patients. However, in many patients treated with PEG-ADA, there is suboptimal immune recovery with low T and B cell numbers. Here, we show reduced thymus cellularity in ADA-SCID mice despite weekly PEG-ADA treatment. This was associated with lack of effective adenosine (Ado) detoxification in the thymus. We also show that thymocyte development in ADA-deficient thymi is arrested at the DN3-to-DN4 stage transition with thymocytes undergoing dATP-induced apoptosis rather than defective TCRβ rearrangement or β-selection. Our studies demonstrate at a detailed level that exogenous once-a-week enzyme replacement does not fully correct intra-thymic metabolic or immunological abnormalities associated with ADA deficiency.

Effects of Artesunate Tablet on Immune Activation and Reconstitution Among Highly Active Antiretroviral Therapy-Treated Patients with Incomplete Immune Responses

The level of T cell activation is a better predictor of CD4+ T cell depletion in highly active antiretroviral therapy (HAART) patients than viral load. Artesunate is an artemisinin derivative that has an immunomodulatory effect. This study investigated whether artesunate tablet reduces T cell activation and improves immune reconstitution among patients with suboptimal immune recovery despite receiving long-term effective HAART. This was a randomized prospective parallel open-label trial consisting of 45 participants whose plasma HIV load was effectively suppressed by HAART for >18 months and who had CD4+ T cell counts of <300 cells/μL or an increase of <20% from baseline. The patients were randomized 2:1 into the artesunate group or the control group and received artesunate tablets (orally, 50 mg two times daily) combined with HAART or HAART alone, respectively. T cell subsets, activation markers, clinical symptoms, viral load, and side effects were assessed. By 48 weeks, artesunate tablet did not improve CD4+ T cell recovery or reduce the activation of T cell subsets but induced in a smaller decline in the expression of T cell activation markers among HAART patients with incomplete immune responses. However, artesunate tablet did appear to reduce the level of T cell apoptosis. One subject developed moderate anemia. Long-term use of artesunate tablet is unlikely to produce substantial clinical benefits in patients receiving HAART who exhibit an incomplete immune response.

Integrase Inhibitors Use and Cytomegalovirus Infection Predict Immune Recovery in People Living With HIV Starting First-Line Therapy.

We explored predictors of CD4/CD8 ratio improvement and optimal immunological recovery (OIR) after initiation of antiretroviral therapy (ART) in naive people living with HIV (PLWH). Retrospective multicenter study including naive PLWH starting ART with 2 nucleos(t)ide reverse transcriptase inhibitors + 1 integrase strand transfer inhibitor (InSTI) or non-NRTI or protease inhibitor (PI). PLWH were followed from the time of ART initiation (baseline) to the discontinuation of first-line regimen, virological failure, death, or loss to follow-up. Estimated incidence and predictors of time to CD4/CD8 ratio normalization (defined as ≥1) and OIR (defined as CD4/CD8 ratio ≥ 1 plus CD4 ≥ 500 cells/µL plus CD4% ≥ 30%) were explored by Kaplan-Meier curves and Cox regression analysis. Overall, 1428 PLWH (77.8% males, median age 39 years, 55.1% with positive cytomegalovirus (CMV) antibodies, median HIV-RNA 4.80 log copies/mL, median CD4 323 cells/µL, median CD4/CD8 ratio 0.32) were included, of which 21.5% (n = 307), 44.5% (n = 636), and 34% (n = 485) treated with InSTI-, PI-, and NNRTI-based regimens, respectively. The estimated proportion of CD4/CD8 normalization and OIR at 36 months was 38.6% and 32.9%, respectively. Multivariate analysis showed that InSTI-based regimens had a higher probability of CD4/CD8 ratio normalization and OIR both in the total population (P < 0.001 versus PI) and in advanced naive PLWH (P ≤ 0.001 versus PI and NNRTI). Moreover, subjects with positive CMV serology showed a lower probability of CD4/CD8 ratio normalization and OIR (P < 0.001). InSTI-based regimens showed a better immune recovery, suggesting that the type of first-line ART can influence immune reconstitution. PLWH with positive CMV serology showed an increased risk of suboptimal immune recovery.

Determinants of suboptimal CD4+ T cell recovery after antiretroviral therapy initiation in a prospective cohort of acute HIV‐1 infection

IntroductionUp to 30% of individuals treated with antiretroviral therapy (ART) during chronic HIV fail to recover CD4 counts to >500 cells/mm3 despite plasma viral suppression. We investigated the frequency and associations of suboptimal CD4 recovery after ART started during acute HIV infection (AHI).MethodsParticipants who started ART in Fiebig I to V AHI with ≥48 weeks of continuous documented HIV‐RNA < 50 copies/mL were stratified by CD4 count at latest study visit to suboptimal immune recovery (SIR; CD4 < 350 cells/mm3), intermediate immune recovery (IIR; 350 ≤ CD4 < 500) and complete immune recovery (CIR; CD4 ≥ 500). Clinical and laboratory parameters were assessed at pre‐ART baseline and latest study visit. Additional inflammatory and neurobehavioral endpoints were examined at baseline and 96 weeks.ResultsOf 304 participants (96% male, median 26 years old) evaluated after median 144 (range 60 to 420) weeks of ART initiated at median 19 days (range 1 to 62) post‐exposure, 3.6% (n = 11) had SIR and 14.5% (n = 44) had IIR. Pre‐ART CD4 count in SIR compared to CIR participants was 265 versus 411 cells/mm3 (p = 0.002). Individuals with SIR or IIR had a slower CD4 rate of recovery compared to those with CIR. Timing of ART initiation by Fiebig stage did not affect CD4 count during treatment. Following ART, the CD8+T cell count (p = 0.001) and CD4/CD8 ratio (p = 0.047) were lower in SIR compared to CIR participants. Compared to the CIR group at week 96, the combined SIR and IIR groups had higher sCD14 (p = 0.008) and lower IL‐6 (p = 0.04) in plasma, without differences in neuropsychological or psychiatric indices.ConclusionsDespite immediate and sustained treatment in AHI, suboptimal CD4 recovery occurs uncommonly and is associated with low pre‐ART CD4 count as well as persistent low CD8 count and CD4/CD8 ratio during treatment.

Characteristics of suboptimal immune response after initiating antiretroviral therapy among people living with HIV with a pre-treatment CD4 T cell count

BackgroundComplete recovery of the CD4 T cell count is uncommon among chronically HIV-infected individuals with very low pre-treatment CD4 count. We studied the prevalence of chronically immune recovery and its associated factors including immune characteristics chronic HIV-infected Thais. MethodsTreatment-naïve participants (n ​= ​375) from the HIV-NAT 006 cohort with a pre-treatment CD4 T cell count after initiating antiretroviral therapy (ART) and having achieved a suppressed viremia (HIV-RNA level ​< ​400 copies/mL) were retrospectively followed at the Thai Red Cross AIDS Research Centre, Bangkok, Thailand. Suboptimal immune recovery (SIR) was defined as having a CD4+ T cell count <200 ​cells/mm3 for 3 years after ART initiation. A case-control sub-study matched for age, sex and pre-ART CD4 T cell count was conducted to compare immunological characteristics between SIR (n ​= ​17) and non-SIR (n ​= ​24) participants. Immunological biomarkers such as interleukin-7 (IL-7) and soluble CD14 (sCD14) and other covariates including cytomegalovirus (CMV) DNA level, baseline hemoglobin level, hepatitis B and C co-infections, and T cell subsets associated with immune activation and exhaustion were evaluated. ResultsAmong 375 participants with pre-ART CD4 T cell counts < 200 ​cells/mm3, the prevalence of SIR was 39.7%, 19.7% and 7.7% at years 1, 2 and 3 after starting ART, respectively. In a multivariate analysis, a pre-ART CD4 T cell count ≤100 ​cells/mm3 (adjusted odds ratio [aOR] 9.45, 95% CI 2.92–30.61, p ​< ​0.001), older age (aOR 1.07, 95% CI 1.01–1.13, p ​= ​0.029) and baseline HIV-RNA level (aOR 0.36, 95% CI 0.21–0.59, p ​< ​0.001) were independently associated with SIR at year 3 after ART initiation. In the matched case-control sub-study (cases ​= ​17, controls ​= ​24), there was a higher prevalence of hepatitis C co-infection (18.8% vs. 0%, p ​= ​0.05), lower sCD14 levels (mean, 6.23 vs. 6.27 log10 ​pg/mL, p ​= ​0.04), lower CD8 T cell counts (mean, 514 vs. 876, p ​= ​0.0003), lower CD4/CD8 T cell ratio (mean, 0.27 vs. 0.41, p ​= ​0.01) and higher expression of PD1 on CD8+ T cells (74.2% vs. 65.1%, p ​= ​0.02) observed in SIR participants compared to their non-SIR counterparts at year 3 after ART initiation. ConclusionsNearly 10% of the study participants who had achieved virological suppression failed to recover a CD4 T cell count > 200 cells/mm3 after 3 years of ART which was with a very low pre-ART CD4 T cell count and older age. The long-term clinical outcomes of SIR participants need to be further explored.

Activated dendritic cells and monocytes in HIV immunological nonresponders: HIV-induced interferon-inducible protein-10 correlates with low future CD4+ recovery.

To explore monocyte and dendritic cell immune responses, and their association with future CD4 gain in treated HIV patients with suboptimal CD4 recovery. A cross-sectional study of HIV-infected, virally suppressed individuals on antiretroviral therapy for at least 24 months; 41 immunological nonresponders (INRs) (CD4 cell count <400 cells/μl) and 26 immunological responders (CD4 cell count >600 cells/μl). Ten HIV-infected antiretroviral therapy-naive and 10 HIV-negative healthy persons served as controls. CD4 cell counts were registered after median 2.4 and 4.7 years. Monocyte, dendritic-cell and T-cell activation and regulatory T cells (Tregs) were analyzed by flow cytometry. In INR and immunological responder subgroups matched on age and nadir CD4 cell count, upregulation of interferon-inducible protein-10 (IP-10) and indoleamine 2,3-dioxygenase in monocytes and dendritic cells and cytokines in cell supernatants were measured in vitro in peripheral blood mononuclear cells stimulated with aldrithiol-2-inactivated HIV-1. The INR group displayed higher spontaneous activation of both monocytes (HLA-DR) and myeloid and plasmacytoid dendritic cells (HLA-DR, CD83 and CD86) compared with immunological responders, and this was associated with increased T-cell activation (CD38HLA-DR), an effector memory T-cell phenotype and activated Tregs. The IP-10 response in monocytes after in-vitro HIV stimulation was negatively associated with prospective CD4 gain. IP-10, indoleamine 2,3-dioxygenase and cytokines levels were comparable between the groups, but inversely correlated with activated Tregs in INRs. HIV-infected individuals with suboptimal immune recovery demonstrated more activated monocytes and in particular dendritic cells, compared with patients with acceptable CD4 gain. A high level of HIV-specific IP-10 expression in monocytes may be predictive of future CD4 recovery.

Enrichment of gut-derived Fusobacterium is associated with suboptimal immune recovery in HIV-infected individuals

We explored the gut microbiota profile among HIV-infected individuals with diverse immune recovery profiles following long-term suppressive ART and investigated the relationship between the altered bacteria with markers of immune dysfunction. The microbiota profile of rectal swabs from 26 HIV-infected individuals and 20 HIV-uninfected controls were examined. Patients were classified as suboptimal responders, sIR (n = 10, CD4 T-cell <350 cells/ul) and optimal responders, oIR (n = 16, CD4 T-cell >500 cells/ul) after a minimum of 2 years on suppressive ART. Canonical correlation analysis(CCA) and multiple regression modelling were used to explore the association between fecal bacterial taxa abundance and immunological profiles in optimal and suboptimal responders. We found Fusobacterium was significantly enriched among the HIV-infected and the sIR group. CCA results showed that Fusobacterium abundance was negatively correlated with CD4 T-cell counts, but positively correlated with CD4 T-cell activation and CD4 Tregs. Multiple linear regression analysis adjusted for age, baseline CD4 T-cell count, antibiotic exposure and MSM status indicated that higher Fusobacterium relative abundance was independently associated with poorer CD4 T-cell recovery following ART. Enrichment of Fusobacterium was associated with reduced immune recovery and persistent immune dysfunction following ART. Modulating the abundance of this bacterial taxa in the gut may be a viable intervention to improve immune reconstitution in our setting.

Suboptimal immune recovery during antiretroviral therapy with sustained HIV suppression in sub-Saharan Africa.

To assess incidence, determinants and clinical consequences of suboptimal immune recovery in HIV-1 infected adults in sub-Saharan Africa with sustained viral suppression on antiretroviral therapy (ART). Multicountry prospective cohort. Suboptimal immune recovery was defined as proportions of participants who failed to attain clinically relevant CD4+ cell count thresholds (>200, >350 and >500 cells/μl) despite sustained viral suppression on continuous first-line ART. Participants were censored at the earliest of death, loss to follow-up, last viral load less than 50 copies/ml, or database closure. Determinants of immune recovery were assessed using multivariable Cox regression. We estimated incidence rates of AIDS, pulmonary tuberculosis and all-cause mortality for CD4+ strata. One thousand, five hundred and ninety-two participants were included; 60% were women, median age was 37 years (IQR 31-43) and median pre-ART CD4+ cell count was 147 cells/μl (IQR 76-215). After 6 years of ART, suboptimal immune recovery at CD4+ cell counts less than 200 cells/μl, less than 350 cells/μl, and less than 500 cells/μl occurred in 7, 27, and 57% of participants, respectively. Compared with participants with CD4+ cell count greater than 500 cells/μl, on-ART incidence rates were 12.5, 4.1, 0.9 times higher for AIDS and 16.9, 3.5, and 2.3 times higher for pulmonary tuberculosis in participants with CD4+ cell count less than 200, 200-349, and 350-499 cells/μl, respectively. All-cause mortality was highest in participants with CD4+ cell count less than 200 cells/μl, and comparable across the higher CD4+ strata. Older age, male sex, and lower pre-ART CD4+ cell count were strongly associated with suboptimal immune recovery. These findings warrant close clinical and laboratory monitoring until adequate immune reconstitution is achieved and support early ART initiation before decline of CD4+ cell count.

Systemic inflammation before and after antiretroviral therapy initiation as a predictor of immune response among HIV-infected individuals in Manitoba

IntroductionDespite the life-prolonging effects of Highly Active Antiretroviral Therapy (HAART), persons with HIV are still prone to higher rates of non-AIDS related morbidity (such as heart, kidney, and liver disease) than the general public. This is likely due to chronic immune activation and inflammation that persists in HIV-positive persons despite virological suppression.What remains undetermined, however, is whether a link exists between chronic inflammation/immune activation and suboptimal immune recovery on HAART.The hypothesis of the present study is that higher levels of systemic subclinical inflammation and immune activation are linked with suboptimal immune recovery on HAART. MethodsFifteen eligible patients from the Manitoba HIV program were enrolled and followed for up to two years; blood samples were drawn at 4 timepoints each, and concentrations of 21 proinflammatory markers were measured. Patients were grouped according to CD4:CD8 recovery at viral suppression, and the inflammatory profiles of the two groups were compared. Results and conclusionsAPRIL and BAFF are higher in those with poor recovery at the point of viral suppression, but were also higher in this group at the onset of therapy and through the three additional follow-up visits. TNF-R1, CD163, and Osteopontin, were also in higher concentrations at the outset of therapy and beyond. These five molecules could thus see potential use in the future as biomarkers of likely poor immune recovery. Future work should focus on replicating these findings with larger cohorts.

Frequency and impact of suboptimal immune recovery on first-line antiretroviral therapy within the International Epidemiologic Databases to Evaluate AIDS in East Africa.

To describe patterns of suboptimal immune recovery (SO-IR) and associated HIV-related-illnesses during the first 5 years following first-line antiretroviral therapy (ART) initiation across seven ART sites in East Africa. Retrospective analysis of data from seven ART clinical sites (three Uganda, two Kenya and two Tanzania). SO-IR was described by proportions of ART-treated adults with CD4 cell counts less than 200, less than 350 and less than 500 cells/μl. Kaplan-Meier survival analysis techniques were used to assess predictors of SO-IR, and incident rates of HIV-related illnesses at CD4 cell counts less than 200, 200-350, 351-499, and >500 cells/μl, respectively. Overall 80 843 adults initiated non-nucleoside reverse transcriptase inhibitor-based first-line ART; 65% were women and median CD4 cell count was 126 [interquartile range (IQR), 52-202] cells/μl. Cumulative probability of SO-IR <200 cells/μl, <350 cells/μl and <500 cells/μl, after 5 years, was 11, 38 and 63%, respectively. Incidence of HIV-related illnesses was higher among those with CD4 cell counts less than 200 and 200-350 cells/μl, than those who achieved CD4 counts above these thresholds. The most common events, at CD4 < 200 cells/μl, were pulmonary tuberculosis [incident rate 15.98 (15.47-16.51)/100 person-years at risk (PYAR), oral candidiasis [incident rate 12.5 (12.03-12.94)] and herpes zoster [incident rate 6.30 (5.99-6.64)] events/100 PYAR. With attainment of a CD4 cell count level 200-350 cells/μl, there was a substantial reduction in events/100 PYAR - by 91% to 1.45 (1.29-1.63) for TB, by 94% to 0.75 (0.64-0.89) for oral candidiasis, by 84% to 0.99 (0.86-1.14) for Herpes Zoster, and by 78% to 1.22 (1.07-1.39) for chronic diarrhea. The incidence of all events decreased further with CD4 counts above these thresholds. Around 40% of adults initiated on ART have suboptimal immune recovery with CD4 counts <350 cells/μl after five years. Such patients will require closer monitoring for both HIV-related and non-HIV-related clinical events.

Unrecognised tuberculosis at antiretroviral therapy initiation is associated with lower CD4+ T cell recovery

To investigate whether an unrecognised diagnosis of tuberculosis (TB) at the start of antiretroviral therapy (ART) influences subsequent CD4+ T cell (CD4) count recovery in an urban HIV clinic in Uganda. In a retrospective cohort study, a multivariable polynomial mixed effects model was used to estimate CD4 recovery in the first 96 weeks of ART in two groups of patients: prevalent TB (started ART while on TB treatment), unrecognised TB (developed TB within 6 months after start ART). Included were 511 patients with a median baseline CD4 count of 57 cells/mm(3) (interquartile range: 22-130), of whom 368 (72%) had prevalent TB and 143 (28%) had unrecognised TB. Compared with prevalent TB, unrecognised TB was associated with lower CD4 count recovery at 96 weeks: -22.3 cells/mm(3) (95% confidence interval -43.2 to -1.5, P = 0.036). These estimates were adjusted for gender, age, baseline CD4 count and the use of zidovudine-based regimen. Unrecognised TB at the time of ART initiation resulted in impaired CD4 recovery compared with TB treated before ART initiation. More vigilant screening with more sensitive and rapid TB diagnostics prior to ART initiation is needed to decrease the risk of ART-associated TB and sub-optimal immune reconstitution.

Long-term effect of efavirenz autoinduction on plasma/peripheral blood mononuclear cell drug exposure and CD4 count is influenced by UGT2B7 and CYP2B6 genotypes among HIV patients

We investigated the long-term effect of efavirenz autoinduction on its plasma/peripheral blood mononuclear cell (PBMC) exposure and the CD4 count, and the importance of sex and pharmacogenetic variations. Treatment-naive HIV patients (n = 163) received efavirenz-based antiretroviral therapy. Plasma and intracellular (PBMC) concentrations of efavirenz and 8-hydroxyefavirenz were determined at weeks 4 and 16 of antiretroviral therapy. CD4 count was determined at baseline, and at weeks 12, 24 and 48. Genotyping for CYP2B6*6, CYP3A5*3, CYP3A5*6, CYP3A5*7, ABCB1 3435C/T and UGT2B7 (-327G→A, *2) was done. There was a significant increase in the median plasma (32%) and intracellular (53%) 8-hydroxyefavirenz concentrations with a decrease in the efavirenz metabolic ratio (MR) (calculated by dividing the concentration of efavirenz by that of 8-hydroxyefavirenz) (20% and 5%, respectively) by week 16 compared with at week 4. While the CYP2B6 genotype significantly influenced efavirenz pharmacokinetics at weeks 4 and 16, the effect of the UGT2B7 genotype and sex was significant only at week 16. The Wilcoxon matched pairs test indicated that the change in 8-hydroxyefavirenz concentration and efavirenz MR over time was significant in females and in CYP2B6*1 and UGT2B7*1 carriers. The intracellular 8-hydroxyefavirenz level at week 16 was a negative predictor of the CD4 count at week 24 (P = 0.03) and at week 48 (P = 0.007). CYP2B6 (P = 0.02) and UGT2B7 (P = 0.05) genotypes predicted the CD4 count at week 48. Among CYP2B6*1/*1 and UGT2B7*1/*1 carriers there was no significant change in the mean CD4 count after week 24, while it continuously increased until week 48 in CYP2B6*6 and UGT2B7*2 carriers. The effects of long-term efavirenz autoinduction on its plasma/PBMC exposure and the CD4 count over time display wide interpatient variability, partly due to sex and CYP2B6 and UGT2B7 genetic variation. Patients with the CYP2B6*1/*1 and UGT2B7*1/*1 genotypes are at risk of suboptimal immune recovery due to pronounced long-term autoinduction.